diff --git a/backend/src/repositories/RemittanceRepository.ts b/backend/src/repositories/RemittanceRepository.ts
index 78cb38a9..78f79d92 100644
--- a/backend/src/repositories/RemittanceRepository.ts
+++ b/backend/src/repositories/RemittanceRepository.ts
@@ -61,44 +61,58 @@ export class RemittanceRepository {
   }
 
   async upsert(record: Omit<TransactionRecord, 'id' | 'created_at' | 'updated_at'>): Promise<void> {
-    await this.pool.query(
-      `INSERT INTO transactions
-         (transaction_id, anchor_id, kind, status, status_eta,
-          amount_in, amount_out, amount_fee, asset_code,
-          stellar_transaction_id, external_transaction_id,
-          kyc_status, kyc_fields, kyc_rejection_reason, message, memo, sender_address, correlation_id)
-       VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14,$15,$16,$17,$18)
-       ON CONFLICT (transaction_id) DO UPDATE SET
-         status                  = EXCLUDED.status,
-         amount_in               = COALESCE(EXCLUDED.amount_in, transactions.amount_in),
-         amount_out              = COALESCE(EXCLUDED.amount_out, transactions.amount_out),
-         amount_fee              = COALESCE(EXCLUDED.amount_fee, transactions.amount_fee),
-         stellar_transaction_id  = COALESCE(EXCLUDED.stellar_transaction_id, transactions.stellar_transaction_id),
-         external_transaction_id = COALESCE(EXCLUDED.external_transaction_id, transactions.external_transaction_id),
-         kyc_status              = COALESCE(EXCLUDED.kyc_status, transactions.kyc_status),
-         message                 = COALESCE(EXCLUDED.message, transactions.message),
-         correlation_id          = COALESCE(EXCLUDED.correlation_id, transactions.correlation_id),
-         updated_at              = NOW()`,
-      [
-        record.transaction_id,
-        record.anchor_id ?? null,
-        record.kind ?? null,
-        record.status ?? null,
-        record.status_eta ?? null,
-        record.amount_in ?? null,
-        record.amount_out ?? null,
-        record.amount_fee ?? null,
-        record.asset_code ?? null,
-        record.stellar_transaction_id ?? null,
-        record.external_transaction_id ?? null,
-        record.kyc_status ?? null,
-        record.kyc_fields ? JSON.stringify(record.kyc_fields) : null,
-        record.kyc_rejection_reason ?? null,
-        record.message ?? null,
-        record.memo ?? null,
-        record.sender_address ?? null,
-        record.correlation_id ?? null,
-      ]
-    );
+    const client = await this.pool.connect();
+    try {
+      await client.query('BEGIN');
+      await client.query(
+        `SELECT id FROM transactions WHERE transaction_id = $1 FOR UPDATE`,
+        [record.transaction_id]
+      );
+      await client.query(
+        `INSERT INTO transactions
+           (transaction_id, anchor_id, kind, status, status_eta,
+            amount_in, amount_out, amount_fee, asset_code,
+            stellar_transaction_id, external_transaction_id,
+            kyc_status, kyc_fields, kyc_rejection_reason, message, memo, sender_address, correlation_id)
+         VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14,$15,$16,$17,$18)
+         ON CONFLICT (transaction_id) DO UPDATE SET
+           status                  = EXCLUDED.status,
+           amount_in               = COALESCE(EXCLUDED.amount_in, transactions.amount_in),
+           amount_out              = COALESCE(EXCLUDED.amount_out, transactions.amount_out),
+           amount_fee              = COALESCE(EXCLUDED.amount_fee, transactions.amount_fee),
+           stellar_transaction_id  = COALESCE(EXCLUDED.stellar_transaction_id, transactions.stellar_transaction_id),
+           external_transaction_id = COALESCE(EXCLUDED.external_transaction_id, transactions.external_transaction_id),
+           kyc_status              = COALESCE(EXCLUDED.kyc_status, transactions.kyc_status),
+           message                 = COALESCE(EXCLUDED.message, transactions.message),
+           correlation_id          = COALESCE(EXCLUDED.correlation_id, transactions.correlation_id),
+           updated_at              = NOW()`,
+        [
+          record.transaction_id,
+          record.anchor_id ?? null,
+          record.kind ?? null,
+          record.status ?? null,
+          record.status_eta ?? null,
+          record.amount_in ?? null,
+          record.amount_out ?? null,
+          record.amount_fee ?? null,
+          record.asset_code ?? null,
+          record.stellar_transaction_id ?? null,
+          record.external_transaction_id ?? null,
+          record.kyc_status ?? null,
+          record.kyc_fields ? JSON.stringify(record.kyc_fields) : null,
+          record.kyc_rejection_reason ?? null,
+          record.message ?? null,
+          record.memo ?? null,
+          record.sender_address ?? null,
+          record.correlation_id ?? null,
+        ]
+      );
+      await client.query('COMMIT');
+    } catch (err) {
+      await client.query('ROLLBACK');
+      throw err;
+    } finally {
+      client.release();
+    }
   }
 }