diff --git a/packages/api/src/router/estimate-version-workflow.ts b/packages/api/src/router/estimate-version-workflow.ts
new file mode 100644
index 0000000..be9d2f4
--- /dev/null
+++ b/packages/api/src/router/estimate-version-workflow.ts
@@ -0,0 +1,194 @@
+import {
+  approveEstimateVersion,
+  createEstimateRevision,
+  submitEstimateVersion,
+} from "@capakraken/application";
+import type { Prisma } from "@capakraken/db";
+import {
+  ApproveEstimateVersionSchema,
+  CreateEstimateRevisionSchema,
+  PermissionKey,
+  SubmitEstimateVersionSchema,
+} from "@capakraken/shared";
+import { TRPCError } from "@trpc/server";
+import { managerProcedure, requirePermission } from "../trpc.js";
+
+type EstimateRouterErrorCode = "NOT_FOUND" | "PRECONDITION_FAILED";
+
+type EstimateRouterErrorRule = {
+  code: EstimateRouterErrorCode;
+  messages?: readonly string[];
+  predicates?: readonly ((message: string) => boolean)[];
+};
+
+function rethrowEstimateRouterError(
+  error: unknown,
+  rules: readonly EstimateRouterErrorRule[],
+): never {
+  if (!(error instanceof Error)) {
+    throw error;
+  }
+
+  const matchingRule = rules.find(
+    (rule) =>
+      rule.messages?.includes(error.message) === true ||
+      rule.predicates?.some((predicate) => predicate(error.message)) === true,
+  );
+
+  if (matchingRule) {
+    throw new TRPCError({
+      code: matchingRule.code,
+      message: error.message,
+    });
+  }
+
+  throw error;
+}
+
+export const estimateVersionWorkflowProcedures = {
+  submitVersion: managerProcedure
+    .input(SubmitEstimateVersionSchema)
+    .mutation(async ({ ctx, input }) => {
+      requirePermission(ctx, PermissionKey.MANAGE_PROJECTS);
+
+      let estimate;
+      try {
+        estimate = await submitEstimateVersion(
+          ctx.db as unknown as Parameters<typeof submitEstimateVersion>[0],
+          input,
+        );
+      } catch (error) {
+        rethrowEstimateRouterError(error, [
+          {
+            code: "NOT_FOUND",
+            messages: ["Estimate not found", "Estimate version not found"],
+          },
+          {
+            code: "PRECONDITION_FAILED",
+            messages: [
+              "Estimate has no working version",
+              "Only working versions can be submitted",
+            ],
+          },
+        ]);
+      }
+
+      await ctx.db.auditLog.create({
+        data: {
+          entityType: "Estimate",
+          entityId: estimate.id,
+          action: "UPDATE",
+          ...(ctx.dbUser?.id ? { userId: ctx.dbUser.id } : {}),
+          changes: {
+            after: {
+              id: estimate.id,
+              status: estimate.status,
+              submittedVersionId: estimate.versions.find(
+                (version) => version.status === "SUBMITTED",
+              )?.id,
+            },
+          } as Prisma.InputJsonValue,
+        },
+      });
+
+      return estimate;
+    }),
+
+  approveVersion: managerProcedure
+    .input(ApproveEstimateVersionSchema)
+    .mutation(async ({ ctx, input }) => {
+      requirePermission(ctx, PermissionKey.MANAGE_PROJECTS);
+
+      let estimate;
+      try {
+        estimate = await approveEstimateVersion(
+          ctx.db as unknown as Parameters<typeof approveEstimateVersion>[0],
+          input,
+        );
+      } catch (error) {
+        rethrowEstimateRouterError(error, [
+          {
+            code: "NOT_FOUND",
+            messages: ["Estimate not found", "Estimate version not found"],
+          },
+          {
+            code: "PRECONDITION_FAILED",
+            messages: [
+              "Estimate has no submitted version",
+              "Only submitted versions can be approved",
+            ],
+          },
+        ]);
+      }
+
+      await ctx.db.auditLog.create({
+        data: {
+          entityType: "Estimate",
+          entityId: estimate.id,
+          action: "UPDATE",
+          ...(ctx.dbUser?.id ? { userId: ctx.dbUser.id } : {}),
+          changes: {
+            after: {
+              id: estimate.id,
+              status: estimate.status,
+              approvedVersionId: estimate.versions.find(
+                (version) => version.status === "APPROVED",
+              )?.id,
+            },
+          } as Prisma.InputJsonValue,
+        },
+      });
+
+      return estimate;
+    }),
+
+  createRevision: managerProcedure
+    .input(CreateEstimateRevisionSchema)
+    .mutation(async ({ ctx, input }) => {
+      requirePermission(ctx, PermissionKey.MANAGE_PROJECTS);
+
+      let estimate;
+      try {
+        estimate = await createEstimateRevision(
+          ctx.db as unknown as Parameters<typeof createEstimateRevision>[0],
+          input,
+        );
+      } catch (error) {
+        rethrowEstimateRouterError(error, [
+          {
+            code: "NOT_FOUND",
+            messages: ["Estimate not found", "Estimate version not found"],
+          },
+          {
+            code: "PRECONDITION_FAILED",
+            messages: [
+              "Estimate already has a working version",
+              "Estimate has no locked version to revise",
+              "Source version must be locked before creating a revision",
+            ],
+          },
+        ]);
+      }
+
+      await ctx.db.auditLog.create({
+        data: {
+          entityType: "Estimate",
+          entityId: estimate.id,
+          action: "UPDATE",
+          ...(ctx.dbUser?.id ? { userId: ctx.dbUser.id } : {}),
+          changes: {
+            after: {
+              id: estimate.id,
+              status: estimate.status,
+              latestVersionNumber: estimate.latestVersionNumber,
+              workingVersionId: estimate.versions.find(
+                (version) => version.status === "WORKING",
+              )?.id,
+            },
+          } as Prisma.InputJsonValue,
+        },
+      });
+
+      return estimate;
+    }),
+};
diff --git a/packages/api/src/router/estimate.ts b/packages/api/src/router/estimate.ts
index 86f589b..7bc8483 100644
--- a/packages/api/src/router/estimate.ts
+++ b/packages/api/src/router/estimate.ts
@@ -1,12 +1,9 @@
 import {
-  approveEstimateVersion,
   cloneEstimate,
   createEstimateExport,
   createEstimate,
   createEstimatePlanningHandoff,
-  createEstimateRevision,
   getEstimateById,
-  submitEstimateVersion,
   updateEstimateDraft,
 } from "@capakraken/application";
 import type { Prisma } from "@capakraken/db";
@@ -19,15 +16,12 @@ import {
   aggregateWeeklyByChapter,
 } from "@capakraken/engine";
 import {
-  ApproveEstimateVersionSchema,
   CloneEstimateSchema,
   CreateEstimateExportSchema,
   CreateEstimatePlanningHandoffSchema,
   CreateEstimateSchema,
-  CreateEstimateRevisionSchema,
   GenerateWeeklyPhasingSchema,
   PermissionKey,
-  SubmitEstimateVersionSchema,
   UpdateEstimateDraftSchema,
 } from "@capakraken/shared";
 import { TRPCError } from "@trpc/server";
@@ -43,6 +37,7 @@ import {
 import { emitAllocationCreated } from "../sse/event-bus.js";
 import { estimateCommercialProcedures } from "./estimate-commercial.js";
 import { estimateReadProcedures } from "./estimate-read.js";
+import { estimateVersionWorkflowProcedures } from "./estimate-version-workflow.js";
 
 type EstimateRouterErrorCode = "NOT_FOUND" | "PRECONDITION_FAILED";
 
@@ -244,6 +239,7 @@ async function autoFillDemandLineRates(
 export const estimateRouter = createTRPCRouter({
   ...estimateReadProcedures,
   ...estimateCommercialProcedures,
+  ...estimateVersionWorkflowProcedures,
 
   create: managerProcedure
     .input(CreateEstimateSchema)
@@ -403,152 +399,6 @@ export const estimateRouter = createTRPCRouter({
       return estimate;
     }),
 
-  submitVersion: managerProcedure
-    .input(SubmitEstimateVersionSchema)
-    .mutation(async ({ ctx, input }) => {
-      requirePermission(ctx, PermissionKey.MANAGE_PROJECTS);
-
-      let estimate;
-      try {
-        estimate = await submitEstimateVersion(
-          ctx.db as unknown as Parameters<typeof submitEstimateVersion>[0],
-          input,
-        );
-      } catch (error) {
-        rethrowEstimateRouterError(error, [
-          {
-            code: "NOT_FOUND",
-            messages: ["Estimate not found", "Estimate version not found"],
-          },
-          {
-            code: "PRECONDITION_FAILED",
-            messages: [
-              "Estimate has no working version",
-              "Only working versions can be submitted",
-            ],
-          },
-        ]);
-      }
-
-      await ctx.db.auditLog.create({
-        data: {
-          entityType: "Estimate",
-          entityId: estimate.id,
-          action: "UPDATE",
-          ...(ctx.dbUser?.id ? { userId: ctx.dbUser.id } : {}),
-          changes: {
-            after: {
-              id: estimate.id,
-              status: estimate.status,
-              submittedVersionId: estimate.versions.find(
-                (version) => version.status === "SUBMITTED",
-              )?.id,
-            },
-          } as Prisma.InputJsonValue,
-        },
-      });
-
-      return estimate;
-    }),
-
-  approveVersion: managerProcedure
-    .input(ApproveEstimateVersionSchema)
-    .mutation(async ({ ctx, input }) => {
-      requirePermission(ctx, PermissionKey.MANAGE_PROJECTS);
-
-      let estimate;
-      try {
-        estimate = await approveEstimateVersion(
-          ctx.db as unknown as Parameters<typeof approveEstimateVersion>[0],
-          input,
-        );
-      } catch (error) {
-        rethrowEstimateRouterError(error, [
-          {
-            code: "NOT_FOUND",
-            messages: ["Estimate not found", "Estimate version not found"],
-          },
-          {
-            code: "PRECONDITION_FAILED",
-            messages: [
-              "Estimate has no submitted version",
-              "Only submitted versions can be approved",
-            ],
-          },
-        ]);
-      }
-
-      await ctx.db.auditLog.create({
-        data: {
-          entityType: "Estimate",
-          entityId: estimate.id,
-          action: "UPDATE",
-          ...(ctx.dbUser?.id ? { userId: ctx.dbUser.id } : {}),
-          changes: {
-            after: {
-              id: estimate.id,
-              status: estimate.status,
-              approvedVersionId: estimate.versions.find(
-                (version) => version.status === "APPROVED",
-              )?.id,
-            },
-          } as Prisma.InputJsonValue,
-        },
-      });
-
-      return estimate;
-    }),
-
-  createRevision: managerProcedure
-    .input(CreateEstimateRevisionSchema)
-    .mutation(async ({ ctx, input }) => {
-      requirePermission(ctx, PermissionKey.MANAGE_PROJECTS);
-
-      let estimate;
-      try {
-        estimate = await createEstimateRevision(
-          ctx.db as unknown as Parameters<typeof createEstimateRevision>[0],
-          input,
-        );
-      } catch (error) {
-        rethrowEstimateRouterError(error, [
-          {
-            code: "NOT_FOUND",
-            messages: ["Estimate not found", "Estimate version not found"],
-          },
-          {
-            code: "PRECONDITION_FAILED",
-            messages: [
-              "Estimate already has a working version",
-              "Estimate has no locked version to revise",
-              "Source version must be locked before creating a revision",
-            ],
-          },
-        ]);
-      }
-
-      await ctx.db.auditLog.create({
-        data: {
-          entityType: "Estimate",
-          entityId: estimate.id,
-          action: "UPDATE",
-          ...(ctx.dbUser?.id ? { userId: ctx.dbUser.id } : {}),
-          changes: {
-            after: {
-              id: estimate.id,
-              status: estimate.status,
-              latestVersionNumber: estimate.latestVersionNumber,
-              workingVersionId: estimate.versions.find(
-                (version) => version.status === "WORKING",
-              )?.id,
-            },
-          } as Prisma.InputJsonValue,
-        },
-      });
-
-      return estimate;
-    }),
-
   createExport: managerProcedure
     .input(CreateEstimateExportSchema)
     .mutation(async ({ ctx, input }) => {