diff --git a/Cargo.lock b/Cargo.lock
index ce59fd8f98..b52a1fd376 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -286,7 +286,7 @@ dependencies = [
 
 [[package]]
 name = "channels_sv2"
-version = "5.0.0"
+version = "5.1.0"
 dependencies = [
  "binary_sv2",
  "bitcoin",
diff --git a/sv2/channels-sv2/Cargo.toml b/sv2/channels-sv2/Cargo.toml
index 1c22cd1e15..e4dae3cf3e 100644
--- a/sv2/channels-sv2/Cargo.toml
+++ b/sv2/channels-sv2/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "channels_sv2"
-version = "5.0.0"
+version = "5.1.0"
 authors = ["The Stratum V2 Developers"]
 edition = "2021"
 readme = "README.md"
diff --git a/sv2/channels-sv2/src/server/extended.rs b/sv2/channels-sv2/src/server/extended.rs
index 899278935b..21e91f5c41 100644
--- a/sv2/channels-sv2/src/server/extended.rs
+++ b/sv2/channels-sv2/src/server/extended.rs
@@ -435,6 +435,11 @@ where
         &self.share_accounting
     }
 
+    /// Updates rejected-share accounting for an emitted `SubmitShares.Error`.
+    pub fn increment_rejected_shares(&mut self, error_code: &str) {
+        self.share_accounting.increment_rejected_shares(error_code);
+    }
+
     /// Updates the channel state with a new template.
     ///
     /// If the template is a future template, the chain tip is not used.
diff --git a/sv2/channels-sv2/src/server/share_accounting.rs b/sv2/channels-sv2/src/server/share_accounting.rs
index a7dd53e49d..b1d7136cdd 100644
--- a/sv2/channels-sv2/src/server/share_accounting.rs
+++ b/sv2/channels-sv2/src/server/share_accounting.rs
@@ -11,15 +11,16 @@
 //!   success, batch acknowledgment, and block discovery.
 //! - **Share Validation Error**: Enumerates possible failure reasons when validating a share.
 //! - **Share Accounting**: Tracks per-channel share statistics, acknowledges batches, detects
-//!   duplicate shares, and maintains best difficulty found.
+//!   duplicate shares, tracks rejected shares, and maintains best difficulty found.
 //!
 //! ## Usage
 //!
 //! Intended for use within mining server implementations that process SV2 share submissions and
-//! issue `SubmitShares.Success` messages. Not intended for use by mining clients.
+//! issue `SubmitShares.Success` or `SubmitShares.Error` messages. Not intended for use by mining
+//! clients.
 
 use bitcoin::hashes::sha256d::Hash;
-use std::collections::HashSet;
+use std::collections::{HashMap, HashSet};
 
 /// The outcome of share validation, from the perspective of a Mining Server.
 ///
@@ -68,11 +69,12 @@ pub enum ShareValidationError {
 /// Standard).
 ///
 /// This struct manages per-channel share statistics, batch acknowledgment, duplicate detection,
-/// and difficulty tracking. Only meant for usage on Mining Servers.
+/// rejected-share accounting, and difficulty tracking. Only meant for usage on Mining Servers.
 #[derive(Clone, Debug)]
 pub struct ShareAccounting {
     last_share_sequence_number: u32,
     shares_accepted: u32,
+    rejected_shares: HashMap<String, u32>,
     share_work_sum: f64,
     last_batch_accepted: u32,
     last_batch_work_sum: f64,
@@ -91,6 +93,7 @@ impl ShareAccounting {
         Self {
             last_share_sequence_number: 0,
             shares_accepted: 0,
+            rejected_shares: HashMap::new(),
             share_work_sum: 0.0,
             last_batch_accepted: 0,
             last_batch_work_sum: 0.0,
@@ -102,6 +105,19 @@ impl ShareAccounting {
         }
     }
 
+    /// Increments rejected-share accounting for an emitted `SubmitShares.Error`.
+    ///
+    /// This should only be called by the application layer after it decides to send a
+    /// `SubmitShares.Error` downstream. Validation errors that are handled internally and do not
+    /// produce `SubmitShares.Error` messages should not be counted here.
+    pub fn increment_rejected_shares(&mut self, error_code: &str) {
+        if let Some(count) = self.rejected_shares.get_mut(error_code) {
+            *count += 1;
+        } else {
+            self.rejected_shares.insert(error_code.to_string(), 1);
+        }
+    }
+
     /// Updates internal accounting for a newly accepted share.
     ///
     /// - Increments total shares accepted and work sum.
@@ -160,6 +176,16 @@ impl ShareAccounting {
         self.shares_accepted
     }
 
+    /// Returns a reference to the map of rejected shares by error code.
+    pub fn get_rejected_shares(&self) -> &HashMap<String, u32> {
+        &self.rejected_shares
+    }
+
+    /// Returns the total number of rejected shares on this channel.
+    pub fn get_rejected_shares_total(&self) -> u32 {
+        self.rejected_shares.values().copied().sum()
+    }
+
     /// Returns the sum of work contributed by all accepted shares.
     ///
     /// Note: this is not what we use for `SubmitShares.Success` messages.
@@ -214,3 +240,33 @@ impl ShareAccounting {
         self.blocks_found
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::ShareAccounting;
+
+    #[test]
+    fn rejected_shares_are_tracked_by_error_code() {
+        let mut accounting = ShareAccounting::new(10);
+
+        accounting.increment_rejected_shares("difficulty-too-low");
+        accounting.increment_rejected_shares("duplicate-share");
+        accounting.increment_rejected_shares("difficulty-too-low");
+
+        assert_eq!(accounting.get_rejected_shares_total(), 3);
+        assert_eq!(
+            accounting
+                .get_rejected_shares()
+                .get("difficulty-too-low")
+                .copied(),
+            Some(2)
+        );
+        assert_eq!(
+            accounting
+                .get_rejected_shares()
+                .get("duplicate-share")
+                .copied(),
+            Some(1)
+        );
+    }
+}
diff --git a/sv2/channels-sv2/src/server/standard.rs b/sv2/channels-sv2/src/server/standard.rs
index 0e07f7e426..73db06d081 100644
--- a/sv2/channels-sv2/src/server/standard.rs
+++ b/sv2/channels-sv2/src/server/standard.rs
@@ -410,6 +410,11 @@ where
         &self.share_accounting
     }
 
+    /// Updates rejected-share accounting for an emitted `SubmitShares.Error`.
+    pub fn increment_rejected_shares(&mut self, error_code: &str) {
+        self.share_accounting.increment_rejected_shares(error_code);
+    }
+
     /// Updates the channel state with a new job.
     ///
     /// If the template is a future template, the chain tip is not used.