diff --git a/app/helpers/submissions_helper.rb b/app/helpers/submissions_helper.rb
index 7e12703c8e..49bcc6e0b8 100644
--- a/app/helpers/submissions_helper.rb
+++ b/app/helpers/submissions_helper.rb
@@ -139,7 +139,8 @@ def submission_link(submission, options)
   def field_selection_tag(request_options, field_info, name_format, enforce_required)
     select_tag(
       name_format % field_info.key,
-      options_for_select(field_info.selection.map(&:to_s), request_options[field_info.key]),
+      options_for_select(field_info.selection.map(&:to_s),
+                         request_options[field_info.key].presence || field_info.default_value),
       class: 'custom-select',
       required: enforce_required && field_info.required,
       read_only: field_info.selection.size == 1
diff --git a/app/models/bulk_submission.rb b/app/models/bulk_submission.rb
index 170ca24bc5..0f29773072 100644
--- a/app/models/bulk_submission.rb
+++ b/app/models/bulk_submission.rb
@@ -253,7 +253,8 @@ def process # rubocop:todo Metrics/CyclomaticComplexity
     'scrna core cells per chip well',
     '% phix requested',
     'low diversity',
-    'ot recipe'
+    'ot recipe',
+    'wafer size'
   ].freeze
 
   ALIAS_FIELDS = { 'plate barcode' => 'barcode', 'tube barcode' => 'barcode' }.freeze
@@ -360,7 +361,8 @@ def extract_request_options(details)
         ['scrna core cells per chip well', 'cells_per_chip_well'],
         ['% phix requested', 'percent_phix_requested'],
         ['low diversity', 'low_diversity'],
-        ['ot recipe', 'ot_recipe']
+        ['ot recipe', 'ot_recipe'],
+        ['wafer size', 'wafer_size']
       ].each do |source_key, target_key|
         assign_value_if_source_present(details, source_key, request_options, target_key)
       end
diff --git a/app/models/ultima_sequencing_pipeline.rb b/app/models/ultima_sequencing_pipeline.rb
index 3a28998d3b..639c7ee349 100644
--- a/app/models/ultima_sequencing_pipeline.rb
+++ b/app/models/ultima_sequencing_pipeline.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-# Specialized sequencing pipeline for Ultima
+# Specialized sequencing pipeline for Ultima UG100
 class UltimaSequencingPipeline < SequencingPipeline
   def ot_recipe_consistent_for_batch?(batch)
     ot_recipe_list = batch.requests.filter_map { |request| request.request_metadata.ot_recipe }
diff --git a/app/models/ultima_ug200_sequencing_pipeline.rb b/app/models/ultima_ug200_sequencing_pipeline.rb
new file mode 100644
index 0000000000..896f4e7696
--- /dev/null
+++ b/app/models/ultima_ug200_sequencing_pipeline.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+# Specialized sequencing pipeline for Ultima UG200
+class UltimaUG200SequencingPipeline < UltimaSequencingPipeline
+  def wafer_size_consistent_for_batch?(batch)
+    wafer_size_list = batch.requests.filter_map { |request| request.request_metadata.wafer_size }
+
+    # There are some requests that don't have the wafer_size attribute
+    return false if wafer_size_list.size != batch.requests.size
+
+    (wafer_size_list.uniq.size == 1)
+  end
+end
diff --git a/app/models/ultima_ug200_sequencing_request.rb b/app/models/ultima_ug200_sequencing_request.rb
new file mode 100644
index 0000000000..0bed36c602
--- /dev/null
+++ b/app/models/ultima_ug200_sequencing_request.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+# Request class specific to the Ultima UG200 sequencing platform.
+# Includes wafer size and OT recipe.
+class UltimaUG200SequencingRequest < SequencingRequest
+  include Api::Messages::UseqWaferIo::LaneExtensions
+
+  FREE = 'Free'
+  FLEX = 'Flex'
+  OT_RECIPE_OPTIONS = [FREE, FLEX].freeze
+
+  has_metadata as: Request do
+    # Defining the sequencing request metadata here again, as 'has_metadata'
+    # does not automatically append these custom attributes to the request.
+    #
+    # The has_metadata call dynamically defines an inner Metadata class and
+    # takes the attributes from the block and adds them to the Metadata class.
+    # There is an assumption that the inner Metadata class is available in a
+    # sequencing request class defintion. Calling has_metadata again does not
+    # inherit the attributes given in the block supplied in the superclass.
+    # They need to be supplied again for this class for a proper inner Metadata
+    # class definition. In a future refactoring these attributes can be moved a
+    # class attribute and subclasses can merge its own attibutes to that. A
+    # common method can set up the inner Metadata class in the subclasses.
+    custom_attribute(:fragment_size_required_from, integer: true, minimum: 1)
+    custom_attribute(:fragment_size_required_to, integer: true, minimum: 1)
+
+    custom_attribute(:ot_recipe, default: FREE, in: OT_RECIPE_OPTIONS, required: true)
+    enum :ot_recipe, { Free: 0, Flex: 1 }
+    custom_attribute(:wafer_size, default: '10TB', validator: true, required: true, selection: true)
+  end
+
+  # Delegate to request_metadata so the attributes are visible to the validator in the RSpec tests.
+  # This delegation has no real effect outside of the tests.
+  delegate :wafer_size, :ot_recipe, to: :request_metadata
+
+  # Generates unique wafer ID, concatenation of batch_for_opentrons,
+  # id_pool_lims, and request_order.
+  # @return [String] unique wafer ID for LIMS
+  def id_wafer_lims
+    "#{batch.id}_#{source_labware.human_barcode}_#{position}"
+  end
+end
diff --git a/app/validators/ultima_ug200_validator.rb b/app/validators/ultima_ug200_validator.rb
new file mode 100644
index 0000000000..ae66f898ad
--- /dev/null
+++ b/app/validators/ultima_ug200_validator.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+class UltimaUG200Validator < UltimaValidator
+  WAFER_SIZE_CONSISTENT_MSG = 'Wafer size must be the same for both requests.'
+
+  # Used in _pipeline_limit.html to display custom validation warnings
+  def self.validation_info
+    'Wafer Size and OT Recipe must be the same for both requests.'
+  end
+
+  # Validates that a batch contains the two requests.
+  def validate(record)
+    validate_exactly_two_requests(record)
+    requests_have_same_ot_recipe(record)
+    requests_have_same_wafer_size(record)
+  end
+
+  private
+
+  def requests_have_same_wafer_size(record)
+    return if record.pipeline.wafer_size_consistent_for_batch?(record)
+
+    record.errors.add(:base, WAFER_SIZE_CONSISTENT_MSG)
+  end
+end
diff --git a/app/views/bulk_submissions/_guidance.html.erb b/app/views/bulk_submissions/_guidance.html.erb
index 6532b2d383..4706dfc832 100644
--- a/app/views/bulk_submissions/_guidance.html.erb
+++ b/app/views/bulk_submissions/_guidance.html.erb
@@ -47,4 +47,5 @@ used to split a submission up into orders, and as a result must have the same re
   <dt>% PhiX requested</dt><dd>Required percentage of PhiX needed.</dd>
   <dt>Low Diversity</dt><dd>Low Diversity value being "Yes" or "No"</dd>
   <dt>OT Recipe</dt><dd>OT (OpenTron liquid handler) Recipe value being "Free" or "Flex"</dd>
+  <dt>Wafer Size</dt><dd>Wafer size value being "5TB", "10TB" or "20TB"</dd>
 </dl>
diff --git a/config/bulk_submission_excel/columns.yml b/config/bulk_submission_excel/columns.yml
index 02de62cb55..8e265391cb 100644
--- a/config/bulk_submission_excel/columns.yml
+++ b/config/bulk_submission_excel/columns.yml
@@ -367,3 +367,22 @@ ot_recipe:
     range_name: :ot_recipe
   conditional_formattings:
     empty_cell:
+wafer_size:
+  heading: "Wafer Size"
+  unlocked: true
+  attribute: :wafer_size
+  validation:
+    options:
+      type: :list
+      formula1: "$A$1:$A$2"
+      allowBlank: false
+      showInputMessage: true
+      showErrorMessage: true
+      errorStyle: :stop
+      errorTitle: "Wafer Size"
+      error: "You must enter a value from the list provided."
+      promptTitle: "Wafer Size"
+      prompt: "Select a value type from the approved list"
+    range_name: :wafer_size
+  conditional_formattings:
+    empty_cell:
diff --git a/config/bulk_submission_excel/ranges.yml b/config/bulk_submission_excel/ranges.yml
index a1c091015a..b211a116cb 100644
--- a/config/bulk_submission_excel/ranges.yml
+++ b/config/bulk_submission_excel/ranges.yml
@@ -27,3 +27,8 @@ ot_recipe:
   options:
     - "Free"
     - "Flex"
+wafer_size:
+  options:
+    - "5TB"
+    - "10TB"
+    - "20TB"
diff --git a/config/default_records/descriptors/005_ultima_ug200_descriptors.wip.yml b/config/default_records/descriptors/005_ultima_ug200_descriptors.wip.yml
new file mode 100644
index 0000000000..df4f31fa60
--- /dev/null
+++ b/config/default_records/descriptors/005_ultima_ug200_descriptors.wip.yml
@@ -0,0 +1,86 @@
+---
+# Section names must be unique inside the record loader folder.
+"OTR carrier Lot # UG200":
+  name: "OTR carrier Lot #"
+  task: Opentrons
+  workflow: Ultima UG200
+  kind: Text
+  required: false
+  sorter: 0
+OTR carrier expiry UG200:
+  name: OTR carrier expiry
+  task: Opentrons
+  workflow: Ultima UG200
+  kind: Date
+  required: false
+  sorter: 1
+"Reaction Mix 7 Lot # UG200":
+  name: "Reaction Mix 7 Lot #"
+  task: Opentrons
+  workflow: Ultima UG200
+  kind: Text
+  required: false
+  sorter: 2
+Reaction Mix 7 expiry UG200:
+  name: Reaction Mix 7 expiry
+  task: Opentrons
+  workflow: Ultima UG200
+  kind: Date
+  required: false
+  sorter: 3
+"NFW Lot # UG200":
+  name: "NFW Lot #"
+  task: Opentrons
+  workflow: Ultima UG200
+  kind: Text
+  required: false
+  sorter: 4
+NFW expiry UG200:
+  name: NFW expiry
+  task: Opentrons
+  workflow: Ultima UG200
+  kind: Date
+  required: false
+  sorter: 5
+"Oil Lot # UG200":
+  name: "Oil Lot #"
+  task: Opentrons
+  workflow: Ultima UG200
+  kind: Text
+  required: false
+  sorter: 6
+Oil expiry UG200:
+  name: Oil expiry
+  task: Opentrons
+  workflow: Ultima UG200
+  kind: Date
+  required: false
+  sorter: 7
+Pipette carousel UG200:
+  name: Pipette carousel
+  task: Opentrons
+  workflow: Ultima UG200
+  kind: Text
+  required: false
+  sorter: 8
+Opentrons Inst. Name UG200:
+  name: Opentrons Inst. Name
+  task: Opentrons
+  workflow: Ultima UG200
+  kind: Text
+  required: true
+  sorter: 9
+Assign Control Bead Tube UG200:
+  name: Assign Control Bead Tube
+  task: Amp
+  workflow: Ultima UG200
+  kind: Text
+  required: false
+  sorter: 0
+UG AMP Inst. Name UG200:
+  name: UG AMP Inst. Name
+  task: Amp
+  workflow: Ultima UG200
+  kind: Text
+  required: true
+  sorter: 1
diff --git a/config/default_records/pipeline_request_information_types/004_ultima_ug200_pipeline_request_information_types.wip.yml b/config/default_records/pipeline_request_information_types/004_ultima_ug200_pipeline_request_information_types.wip.yml
new file mode 100644
index 0000000000..76a81c2576
--- /dev/null
+++ b/config/default_records/pipeline_request_information_types/004_ultima_ug200_pipeline_request_information_types.wip.yml
@@ -0,0 +1,16 @@
+---
+FragmentSizeRequiredFromInformationTypeForUltimaUG200:
+  pipeline_name: Ultima UG200
+  request_information_type_key: fragment_size_required_from
+
+FragmentSizeRequiredToInformationTypeForUltimaUG200:
+  pipeline_name: Ultima UG200
+  request_information_type_key: fragment_size_required_to
+
+WaferSizeInformationTypeForUltimaUG200:
+  pipeline_name: Ultima UG200
+  request_information_type_key: wafer_size
+
+OTRecipeInformationTypeForUltimaUG200:
+  pipeline_name: Ultima UG200
+  request_information_type_key: ot_recipe
diff --git a/config/default_records/pipelines/004_ultima_ug200_pipelines.wip.yml b/config/default_records/pipelines/004_ultima_ug200_pipelines.wip.yml
new file mode 100644
index 0000000000..21b128df05
--- /dev/null
+++ b/config/default_records/pipelines/004_ultima_ug200_pipelines.wip.yml
@@ -0,0 +1,17 @@
+---
+Ultima UG200:
+  name: Ultima UG200 Sequencing
+  sti_type: UltimaUG200SequencingPipeline
+  validator_class_name: UltimaUG200Validator
+  sorter: 10
+  max_size: 2
+  summary: 1
+  externally_managed: 0
+  group_name: Sequencing
+  control_request_type_id: 0
+  min_size: 1
+  request_type_keys:
+    - ultima_ug200_sequencing
+  workflow:
+    name: Ultima UG200
+    item_limit: 2
diff --git a/config/default_records/plate_purposes/017_ultima_ug200_purposes.wip.yml b/config/default_records/plate_purposes/017_ultima_ug200_purposes.wip.yml
new file mode 100644
index 0000000000..682ce88e23
--- /dev/null
+++ b/config/default_records/plate_purposes/017_ultima_ug200_purposes.wip.yml
@@ -0,0 +1,9 @@
+---
+# 96 well input plates
+UPF2 Cherrypicked:
+  type: PlatePurpose::Input
+  stock_plate: true
+  default_state: passed
+  cherrypickable_target: true
+  target_type: Plate
+  size: 96
diff --git a/config/default_records/request_information_types/004_ultima_ug200_request_information_types.wip.yml b/config/default_records/request_information_types/004_ultima_ug200_request_information_types.wip.yml
new file mode 100644
index 0000000000..bde23fdb31
--- /dev/null
+++ b/config/default_records/request_information_types/004_ultima_ug200_request_information_types.wip.yml
@@ -0,0 +1,7 @@
+---
+wafer_size:
+  name: Wafer size
+  key: wafer_size
+  label: Wafer size
+  width: 5
+  hide_in_inbox: 0
diff --git a/config/default_records/request_type_validators/003_ultima_ug200_request_type_validators.wip.yml b/config/default_records/request_type_validators/003_ultima_ug200_request_type_validators.wip.yml
new file mode 100644
index 0000000000..028e593253
--- /dev/null
+++ b/config/default_records/request_type_validators/003_ultima_ug200_request_type_validators.wip.yml
@@ -0,0 +1,8 @@
+---
+WaferSizeRequestedUltimaUG200Sequencing:
+  request_type_key: ultima_ug200_sequencing
+  request_option: wafer_size
+  valid_options:
+    - 5TB
+    - 10TB
+    - 20TB
diff --git a/config/default_records/request_types/026_ultima_ug200_request_types.wip.yml b/config/default_records/request_types/026_ultima_ug200_request_types.wip.yml
new file mode 100644
index 0000000000..bc5977f439
--- /dev/null
+++ b/config/default_records/request_types/026_ultima_ug200_request_types.wip.yml
@@ -0,0 +1,31 @@
+# Request types for Ultima UG200 sequencing platform.
+---
+limber_ultima_ug200_htp_pcr_free:
+  name: Limber Ultima UG200 HTP PCR Free
+  order: 1
+  request_class_name: IlluminaHtp::Requests::StdLibraryRequest
+  asset_type: Well
+  for_multiplexing: false
+  billable: true
+  product_line_name: Ultima # same as UG100
+  acceptable_purposes:
+    - UPF2 Cherrypicked
+  library_types:
+    - Ultima High Throughput PCR Free 96 # same as UG100
+limber_multiplexing_ultima_ug200:
+  name: Limber Multiplexing Ultima UG200
+  asset_type: Well
+  order: 2
+  request_class_name: Request::Multiplexing
+  for_multiplexing: true
+  product_line_name: Ultima # same as UG100
+  target_purpose_name: UPF2 EqVol Norm
+ultima_ug200_sequencing:
+  name: Ultima UG200 sequencing
+  asset_type: LibraryTube
+  order: 2
+  initial_state: pending
+  billable: true
+  product_line_name: Ultima # same as UG100
+  request_class_name: UltimaUG200SequencingRequest
+  request_purpose: standard
diff --git a/config/default_records/submission_templates/021_ultima_ug200_submission_templates.wip.yml b/config/default_records/submission_templates/021_ultima_ug200_submission_templates.wip.yml
new file mode 100644
index 0000000000..5c534184d0
--- /dev/null
+++ b/config/default_records/submission_templates/021_ultima_ug200_submission_templates.wip.yml
@@ -0,0 +1,18 @@
+# This submission template is associated with the Ultima PCR Free Library preparation pipeline
+# and the Ultima UG200 sequencing platform.
+---
+Limber-Htp - Ultima UG200 PCR Free - Ultima UG200 sequencing:
+  submission_class_name: "LinearSubmission"
+  related_records:
+    request_type_keys:
+      ["limber_ultima_ug200_htp_pcr_free", "limber_multiplexing_ultima_ug200", "ultima_ug200_sequencing"]
+    order_role: PCR Free
+    product_line_name: Ultima # same as UG100
+    product_catalogue_name: GenericNoPCR
+Limber-Htp - Ultima UG200 PCR Free - Ultima UG200 sequencing Automated:
+  submission_class_name: "LinearSubmission"
+  related_records:
+    request_type_keys: ["ultima_ug200_sequencing"]
+    order_role: PCR Free
+    product_line_name: Ultima # same as UG100
+    product_catalogue_name: GenericNoPCR
diff --git a/config/default_records/tasks/005_ultima_ug200_tasks.wip.yml b/config/default_records/tasks/005_ultima_ug200_tasks.wip.yml
new file mode 100644
index 0000000000..a72c05029d
--- /dev/null
+++ b/config/default_records/tasks/005_ultima_ug200_tasks.wip.yml
@@ -0,0 +1,14 @@
+---
+# Section names must be unique inside the record loader folder.
+Opentrons UG200:
+  name: Opentrons
+  workflow: Ultima UG200
+  sorted: 0
+  lab_activity: true
+  sti_type: SetDescriptorsTask
+Amp UG200:
+  name: Amp
+  workflow: Ultima UG200
+  sorted: 1
+  lab_activity: true
+  sti_type: SetDescriptorsTask
diff --git a/config/default_records/tube_purposes/011_ultima_ug200_tube_purposes.wip.yml b/config/default_records/tube_purposes/011_ultima_ug200_tube_purposes.wip.yml
new file mode 100644
index 0000000000..3cb41b6b30
--- /dev/null
+++ b/config/default_records/tube_purposes/011_ultima_ug200_tube_purposes.wip.yml
@@ -0,0 +1,6 @@
+---
+UPF2 EqVol Norm:
+  # Even though this is Ultima, not Illumina, the MX tube has the same behaviour
+  type: IlluminaHtp::MxTubePurpose
+  target_type: MultiplexedLibraryTube
+  stock_plate: false
diff --git a/config/initializers/inflections.rb b/config/initializers/inflections.rb
index 1b0cac6328..d3ad112180 100644
--- a/config/initializers/inflections.rb
+++ b/config/initializers/inflections.rb
@@ -16,6 +16,7 @@
   inflect.acronym 'ENA' # European Nucleotide Archive
   inflect.acronym 'HTTP' # HyperText Transfer Protocol
   inflect.acronym 'EBI'  # European Bioinformatics Institute
+  inflect.acronym 'UG200' # Ultima UG200
 end
 
 # These inflection rules are supported but not enabled by default:
diff --git a/config/locales/metadata/en.yml b/config/locales/metadata/en.yml
index 08f1fbd67e..da8fa0683b 100644
--- a/config/locales/metadata/en.yml
+++ b/config/locales/metadata/en.yml
@@ -79,6 +79,9 @@ en:
         ot_recipe:
           label: OT Recipe
 
+        wafer_size:
+          label: Wafer Size
+
     library_creation_request:
       <<: *REQUEST
     sequencing_request:
@@ -107,6 +110,9 @@ en:
     ultima_sequencing_request:
       <<: *REQUEST
 
+    ultima_ug200_sequencing_request:
+      <<: *REQUEST
+
     pulldown:
       requests:
         wgs_library_request:
diff --git a/db/migrate/20260324112536_add_wafer_size_to_request_metadata.rb b/db/migrate/20260324112536_add_wafer_size_to_request_metadata.rb
new file mode 100644
index 0000000000..f1e811d8f0
--- /dev/null
+++ b/db/migrate/20260324112536_add_wafer_size_to_request_metadata.rb
@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+# This migration adds a wafer_size column to the request_metadata table, which is used to store
+# the wafer size for Ultima sequencing requests. This is stored as a string, with possible
+# values of 5TB, 10TB, and 20TB at time of writing.
+class AddWaferSizeToRequestMetadata < ActiveRecord::Migration[7.1]
+  def change
+    add_column :request_metadata, :wafer_size, :string
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 34cce1cefe..4f5e30ff8a 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.2].define(version: 2026_03_17_142326) do
+ActiveRecord::Schema[7.2].define(version: 2026_03_24_112536) do
   create_table "accession_sample_statuses", charset: "utf8mb4", collation: "utf8mb4_unicode_ci", force: :cascade do |t|
     t.integer "sample_id", null: false
     t.string "status", null: false
@@ -1191,6 +1191,7 @@
     t.boolean "low_diversity"
     t.integer "percent_phix_requested"
     t.integer "ot_recipe"
+    t.string "wafer_size"
     t.index ["request_id"], name: "index_request_metadata_on_request_id"
   end
 
diff --git a/spec/data/bulk_submission_excel/columns.yml b/spec/data/bulk_submission_excel/columns.yml
index 03280783ee..ab5bd8739e 100644
--- a/spec/data/bulk_submission_excel/columns.yml
+++ b/spec/data/bulk_submission_excel/columns.yml
@@ -315,3 +315,22 @@ ot_recipe:
     range_name: :ot_recipe
   conditional_formattings:
     empty_cell:
+wafer_size:
+  heading: "Wafer Size"
+  unlocked: true
+  attribute: :wafer_size
+  validation:
+    options:
+      type: :list
+      formula1: "$A$1:$A$2"
+      allowBlank: false
+      showInputMessage: true
+      showErrorMessage: true
+      errorStyle: :stop
+      errorTitle: "Wafer Size"
+      error: "You must enter a value from the list provided."
+      promptTitle: "Wafer Size"
+      prompt: "Select a value type from the approved list"
+    range_name: :wafer_size
+  conditional_formattings:
+    empty_cell:
diff --git a/spec/data/bulk_submission_excel/ranges.yml b/spec/data/bulk_submission_excel/ranges.yml
index a1c091015a..b211a116cb 100644
--- a/spec/data/bulk_submission_excel/ranges.yml
+++ b/spec/data/bulk_submission_excel/ranges.yml
@@ -27,3 +27,8 @@ ot_recipe:
   options:
     - "Free"
     - "Flex"
+wafer_size:
+  options:
+    - "5TB"
+    - "10TB"
+    - "20TB"
diff --git a/spec/factories/request_factories.rb b/spec/factories/request_factories.rb
index 5a012985fc..ad180e5d76 100644
--- a/spec/factories/request_factories.rb
+++ b/spec/factories/request_factories.rb
@@ -124,6 +124,20 @@
     end
   end
 
+  factory(:ultima_ug200_sequencing_request) do
+    request_type factory: %i[ultima_ug200_sequencing]
+    request_purpose { :standard }
+    sti_type { 'UltimaUG200SequencingRequest' }
+    request_metadata_attributes do
+      {
+        fragment_size_required_from: 150,
+        fragment_size_required_to: 400,
+        ot_recipe: 'Free',
+        wafer_size: '10TB'
+      }
+    end
+  end
+
   factory(:library_creation_request, parent: :request, class: 'LibraryCreationRequest') do
     asset factory: %i[sample_tube]
     request_type factory: %i[library_creation_request_type]
diff --git a/spec/factories/request_type_factories.rb b/spec/factories/request_type_factories.rb
index 4d18e1eb3d..87b2fecfd4 100644
--- a/spec/factories/request_type_factories.rb
+++ b/spec/factories/request_type_factories.rb
@@ -139,6 +139,11 @@
       request_class { UltimaSequencingRequest }
     end
 
+    factory :ultima_ug200_sequencing do
+      asset_type { 'LibraryTube' }
+      request_class { UltimaUG200SequencingRequest }
+    end
+
     factory :miseq_sequencing_request_type do
       request_class { MiSeqSequencingRequest }
       asset_type { 'LibraryTube' }
diff --git a/spec/helpers/submissions_helper_spec.rb b/spec/helpers/submissions_helper_spec.rb
new file mode 100644
index 0000000000..5e5101c42c
--- /dev/null
+++ b/spec/helpers/submissions_helper_spec.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe SubmissionsHelper do
+  describe '#field_input_tag' do
+    let(:field_info) do
+      double(
+        kind: 'Selection',
+        key: :ot_recipe,
+        selection: %w[Free Flex],
+        default_value: 'Free',
+        required: true
+      )
+    end
+
+    let(:wafer_size_field_info) do
+      double(
+        kind: 'Selection',
+        key: :wafer_size,
+        selection: %w[5TB 10TB],
+        default_value: '10TB',
+        required: true
+      )
+    end
+
+    it 'uses the default value for selection fields when no request option is set' do
+      html = helper.field_input_tag(field_info, values: {}, name_format: 'submission[order_params][%s]')
+
+      expect(html).to include('<option selected="selected" value="Free">Free</option>')
+    end
+
+    it 'uses the default value for selection fields when request option is blank' do
+      html = helper.field_input_tag(field_info, values: { ot_recipe: '' }, name_format: 'submission[order_params][%s]')
+
+      expect(html).to include('<option selected="selected" value="Free">Free</option>')
+    end
+
+    it 'uses the default wafer_size when request option is blank' do
+      html = helper.field_input_tag(wafer_size_field_info,
+                                    values: { wafer_size: '' },
+                                    name_format: 'submission[order_params][%s]')
+
+      expect(html).to include('<option selected="selected" value="10TB">10TB</option>')
+    end
+  end
+end
diff --git a/spec/models/ultima_sequencing_request_spec.rb b/spec/models/ultima_sequencing_request_spec.rb
index d152679b4e..3cbaa4864f 100644
--- a/spec/models/ultima_sequencing_request_spec.rb
+++ b/spec/models/ultima_sequencing_request_spec.rb
@@ -33,7 +33,7 @@
     end
 
     context 'when ot_recipe value is not assigned' do
-      it 'is invalid and displays required percent phix requested error message' do
+      it 'is invalid and displays required OT recipe error message' do
         request.request_metadata.ot_recipe = nil
         request.validate
         expect(request.errors[:'request_metadata.ot_recipe']).to include("can't be blank")
diff --git a/spec/models/ultima_ug200_sequencing_pipeline_spec.rb b/spec/models/ultima_ug200_sequencing_pipeline_spec.rb
new file mode 100644
index 0000000000..361bce75a5
--- /dev/null
+++ b/spec/models/ultima_ug200_sequencing_pipeline_spec.rb
@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+require 'rails_helper'
+
+RSpec.describe UltimaUG200SequencingPipeline do
+  let(:pipeline) do
+    described_class.new(
+      workflow: Workflow.new,
+      request_types: [create(:ultima_ug200_sequencing)]
+    )
+  end
+
+  describe '#ot_recipe_consistent_for_batch?' do
+    it 'returns true when all requests have the same ot_recipe' do
+      batch = pipeline.batches.build
+      r1 = create(:ultima_ug200_sequencing_request, request_metadata_attributes: { ot_recipe: 'Free' })
+      r2 = create(:ultima_ug200_sequencing_request, request_metadata_attributes: { ot_recipe: 'Free' })
+      batch.requests << [r1, r2]
+
+      expect(pipeline.ot_recipe_consistent_for_batch?(batch)).to be true
+    end
+
+    it 'returns false when requests have different ot_recipes' do
+      batch = pipeline.batches.build
+      req1 = create(:ultima_ug200_sequencing_request, request_metadata_attributes: { ot_recipe: 'Free' })
+      req2 = create(:ultima_ug200_sequencing_request, request_metadata_attributes: { ot_recipe: 'Flex' })
+      batch.requests << [req1, req2]
+
+      expect(pipeline.ot_recipe_consistent_for_batch?(batch)).to be false
+    end
+
+    it 'returns false when some requests are missing ot_recipe' do
+      batch = pipeline.batches.build
+      r1 = create(:sequencing_request, request_metadata_attributes: { ot_recipe: 'Free' })
+      r2 = create(:sequencing_request, request_metadata_attributes: {}) # no ot_recipe
+      batch.requests << [r1, r2]
+
+      expect(pipeline.ot_recipe_consistent_for_batch?(batch)).to be false
+    end
+  end
+
+  describe '#wafer_size_consistent_for_batch?' do
+    it 'returns true when all requests have the same wafer_size' do
+      batch = pipeline.batches.build
+      r1 = create(:ultima_ug200_sequencing_request, request_metadata_attributes: { wafer_size: '10TB' })
+      r2 = create(:ultima_ug200_sequencing_request, request_metadata_attributes: { wafer_size: '10TB' })
+      batch.requests << [r1, r2]
+
+      expect(pipeline.wafer_size_consistent_for_batch?(batch)).to be true
+    end
+
+    it 'returns false when requests have different wafer_sizes' do
+      batch = pipeline.batches.build
+      req1 = create(:ultima_ug200_sequencing_request, request_metadata_attributes: { wafer_size: '5TB' })
+      req2 = create(:ultima_ug200_sequencing_request, request_metadata_attributes: { wafer_size: '10TB' })
+      batch.requests << [req1, req2]
+
+      expect(pipeline.wafer_size_consistent_for_batch?(batch)).to be false
+    end
+
+    # NB. Wafer size is a required field, so cannot be missing. Tested in the request spec.
+  end
+
+  describe '#post_release_batch' do
+    let(:batch) { create(:batch) }
+
+    it 'calls Messenger with UseqWaferIo template and useq_wafer root' do
+      allow(Messenger).to receive(:create!)
+      pipeline.post_release_batch(batch, create(:user))
+
+      expect(Messenger).to have_received(:create!).with(
+        hash_including(target: batch, template: 'UseqWaferIo', root: 'useq_wafer')
+      )
+    end
+  end
+end
diff --git a/spec/models/ultima_ug200_sequencing_request_spec.rb b/spec/models/ultima_ug200_sequencing_request_spec.rb
new file mode 100644
index 0000000000..a87bc38fd2
--- /dev/null
+++ b/spec/models/ultima_ug200_sequencing_request_spec.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe UltimaUG200SequencingRequest do
+  let(:request) { create(:ultima_ug200_sequencing_request) }
+
+  describe 'Validations' do
+    context 'when all attributes are valid' do
+      it 'is valid' do
+        expect(request).to be_valid
+      end
+    end
+
+    context 'when fragment_size_required_from is less than 1' do
+      it 'is invalid and displays fragment size from error message' do
+        request.request_metadata.fragment_size_required_from = 0
+        request.validate
+        expect(request.errors[:'request_metadata.fragment_size_required_from']).to include(
+          'must be greater than or equal to 1'
+        )
+      end
+    end
+
+    context 'when fragment_size_required_to is less than 1' do
+      it 'is invalid and displays fragment size to error message' do
+        request.request_metadata.fragment_size_required_to = 0
+        request.validate
+        expect(request.errors[:'request_metadata.fragment_size_required_to']).to include(
+          'must be greater than or equal to 1'
+        )
+      end
+    end
+
+    context 'when wafer_size value is not assigned' do
+      it 'is invalid and displays required wafer size error message' do
+        request.request_metadata.wafer_size = nil
+        request.validate
+        expect(request.errors[:'request_metadata.wafer_size']).to include("can't be blank")
+      end
+    end
+
+    context 'when ot_recipe value is not assigned' do
+      it 'is invalid and displays required OT recipe error message' do
+        request.request_metadata.ot_recipe = nil
+        request.validate
+        expect(request.errors[:'request_metadata.ot_recipe']).to include("can't be blank")
+      end
+    end
+  end
+end
diff --git a/spec/validators/ultima_ug200_validator_spec.rb b/spec/validators/ultima_ug200_validator_spec.rb
new file mode 100644
index 0000000000..34082981cb
--- /dev/null
+++ b/spec/validators/ultima_ug200_validator_spec.rb
@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+require 'rails_helper'
+
+describe UltimaUG200Validator do
+  describe '#validate' do
+    subject(:validator) { described_class.new }
+
+    let(:pipeline) { UltimaUG200SequencingPipeline.new }
+    let(:batch) { create(:batch, pipeline:) }
+    let(:requests) { [request1, request2] }
+    let(:request1_metadata) { { ot_recipe: 'Free', wafer_size: '10TB' } }
+    let(:request2_metadata) { { ot_recipe: 'Free', wafer_size: '10TB' } }
+    let(:request1) { create(:ultima_sequencing_request, request_metadata_attributes: request1_metadata) }
+    let(:request2) { create(:ultima_sequencing_request, request_metadata_attributes: request2_metadata) }
+
+    before do
+      batch.requests << requests
+    end
+
+    context 'when batch contains two requests with the same OT Recipe' do
+      it 'is valid' do
+        validator.validate(batch)
+        expect(batch.errors[:base]).to be_empty
+      end
+    end
+
+    context 'when batch contains two requests with different ot_recipe' do
+      let(:request2_metadata) { { ot_recipe: 'Flex', wafer_size: '10TB' } }
+
+      it 'is invalid due to ot_recipe mismatch' do
+        validator.validate(batch)
+        expect(batch.errors[:base]).to include(described_class::OT_RECIPE_CONSISTENT_MSG)
+      end
+    end
+
+    context 'when batch contains two requests with the same Wafer Size' do
+      it 'is valid' do
+        validator.validate(batch)
+        expect(batch.errors[:base]).not_to include(described_class::WAFER_SIZE_CONSISTENT_MSG)
+      end
+    end
+
+    context 'when batch contains two requests with different wafer_size' do
+      let(:request1_metadata) { { ot_recipe: 'Free', wafer_size: '5TB' } }
+
+      it 'is invalid due to wafer_size mismatch' do
+        validator.validate(batch)
+        expect(batch.errors[:base]).to include(described_class::WAFER_SIZE_CONSISTENT_MSG)
+      end
+    end
+
+    context 'when batch contains a single request' do
+      let(:requests) { [request1] }
+
+      it 'is invalid' do
+        validator.validate(batch)
+        expect(batch.errors[:base]).to include(described_class::TWO_REQUESTS_MSG)
+      end
+    end
+  end
+end
diff --git a/test/controllers/batches_controller_test.rb b/test/controllers/batches_controller_test.rb
index a109e47d21..a7810bbefd 100644
--- a/test/controllers/batches_controller_test.rb
+++ b/test/controllers/batches_controller_test.rb
@@ -257,6 +257,9 @@ class BatchesControllerTest < ActionController::TestCase
                  "request_group_#{@plate.id}_#{@submission.id}_size": '1',
                  commit: 'Submit'
                }
+
+          assert_redirected_to batch_path(assigns(:batch))
+          assert_predicate assigns(:batch), :persisted?
         end
       end
 
diff --git a/test/lib/label_printer/plate_to_tube_test.rb b/test/lib/label_printer/plate_to_tube_test.rb
index 49bb24fbb4..6a289237cc 100644
--- a/test/lib/label_printer/plate_to_tube_test.rb
+++ b/test/lib/label_printer/plate_to_tube_test.rb
@@ -13,7 +13,12 @@ def setup # rubocop:todo Metrics/AbcSize
     @barcode1 = '1111'
     @asset_name = 'tube name'
     @tube1 = create(:sample_tube, :tube_barcode, barcode: barcode1, prefix: prefix, name: asset_name)
-    @sample_tubes = create_list(:sample_tube, 4, :tube_barcode)
+    @sample_tubes = [
+      create(:sample_tube, :tube_barcode, barcode: '2222', prefix: prefix),
+      create(:sample_tube, :tube_barcode, barcode: '3333', prefix: prefix),
+      create(:sample_tube, :tube_barcode, barcode: '4444', prefix: prefix),
+      create(:sample_tube, :tube_barcode, barcode: '5555', prefix: prefix)
+    ]
     sample_tubes.unshift(tube1)
     options = { sample_tubes: }
     @tube_label = LabelPrinter::Label::PlateToTubes.new(options)
diff --git a/test/unit/batch_test.rb b/test/unit/batch_test.rb
index abfc223aef..e9d8ae10a5 100644
--- a/test/unit/batch_test.rb
+++ b/test/unit/batch_test.rb
@@ -647,7 +647,7 @@ class BatchTest < ActiveSupport::TestCase
     end
 
     should 'check that with the pipeline that the batch is valid' do
-      @batch.complete!(@user)
+      assert_nothing_raised { @batch.complete!(@user) }
     end
   end
 
diff --git a/test/unit/event_test.rb b/test/unit/event_test.rb
index 67e6a550e7..68fe62686c 100644
--- a/test/unit/event_test.rb
+++ b/test/unit/event_test.rb
@@ -18,7 +18,7 @@ class EventTest < ActiveSupport::TestCase
           setup { @event = Event.create(descriptor_key: '') }
 
           should 'be valid' do
-            @event.valid?
+            assert_predicate @event, :valid?
           end
         end
       end
@@ -28,7 +28,7 @@ class EventTest < ActiveSupport::TestCase
           setup { @event = Event.create }
 
           should 'be valid' do
-            @event.valid?
+            assert_predicate @event, :valid?
           end
         end
       end
diff --git a/test/unit/request_factory_test.rb b/test/unit/request_factory_test.rb
index 5339e13433..538b6eaacc 100644
--- a/test/unit/request_factory_test.rb
+++ b/test/unit/request_factory_test.rb
@@ -42,7 +42,7 @@ class RequestcreateTest < ActiveSupport::TestCase
         setup { @project.update!(enforce_quotas: true) }
 
         should 'not fail' do
-          RequestFactory.copy_request(@request)
+          assert_nothing_raised { RequestFactory.copy_request(@request) }
         end
       end
     end
diff --git a/test/unit/sequencing_qc_batch_test.rb b/test/unit/sequencing_qc_batch_test.rb
index 89a123a9bb..eda3f8a081 100644
--- a/test/unit/sequencing_qc_batch_test.rb
+++ b/test/unit/sequencing_qc_batch_test.rb
@@ -38,6 +38,7 @@ class SequencingQcBatchTest < ActiveSupport::TestCase
 
       should 'do nothing if the next state is nil' do
         @batch.stubs(:qc_next_state).returns(nil)
+        @batch.expects(:update_attribute).never # no state update when there is no next state
         @batch.qc_submitted
       end
     end
@@ -51,6 +52,7 @@ class SequencingQcBatchTest < ActiveSupport::TestCase
 
       should 'do nothing if the next state is nil' do
         @batch.stubs(:qc_next_state).returns(nil)
+        @batch.expects(:update_attribute).never # no state update when there is no next state
         @batch.qc_criteria_received
       end
     end
@@ -64,6 +66,7 @@ class SequencingQcBatchTest < ActiveSupport::TestCase
 
       should 'do nothing if the next state is nil' do
         @batch.stubs(:qc_next_state).returns(nil)
+        @batch.expects(:update_attribute).never # no state update when there is no next state
         @batch.qc_complete
       end
     end
diff --git a/test/unit/tasks/plate_transfer_task_test.rb b/test/unit/tasks/plate_transfer_task_test.rb
index 9ed5ba55f8..669a0df93d 100644
--- a/test/unit/tasks/plate_transfer_task_test.rb
+++ b/test/unit/tasks/plate_transfer_task_test.rb
@@ -100,6 +100,7 @@ class PlateTransferTaskTest < ActiveSupport::TestCase
         end
 
         should 'find the existing plate' do
+          assert_equal 1, Plate.count - @plate_count
         end
       end
 
diff --git a/test/unit/user_test.rb b/test/unit/user_test.rb
index 126e8414d0..081be0ac56 100644
--- a/test/unit/user_test.rb
+++ b/test/unit/user_test.rb
@@ -123,7 +123,7 @@ class UserTest < ActiveSupport::TestCase
 
       should 'be able to have one assigned' do
         code = 'code'
-        @user.swipecard_code = code
+        assert_nothing_raised { @user.swipecard_code = code }
       end
     end