diff --git a/packages/api/src/__tests__/management-level-support.test.ts b/packages/api/src/__tests__/management-level-support.test.ts
new file mode 100644
index 0000000..2cf316b
--- /dev/null
+++ b/packages/api/src/__tests__/management-level-support.test.ts
@@ -0,0 +1,71 @@
+import { TRPCError } from "@trpc/server";
+import { describe, expect, it, vi } from "vitest";
+import {
+  assertManagementLevelDeletable,
+  assertManagementLevelGroupNameAvailable,
+  assertManagementLevelNameAvailable,
+  buildManagementLevelCreateData,
+  buildManagementLevelGroupCreateData,
+  buildManagementLevelGroupUpdateData,
+  buildManagementLevelUpdateData,
+} from "../router/management-level-support.js";
+
+describe("management level support", () => {
+  it("rejects duplicate group names outside the ignored id", async () => {
+    const db = {
+      managementLevelGroup: {
+        findUnique: vi.fn().mockResolvedValue({ id: "group_existing", name: "Team Leads" }),
+      },
+    } as never;
+
+    await expect(assertManagementLevelGroupNameAvailable(db, "Team Leads")).rejects.toBeInstanceOf(TRPCError);
+  });
+
+  it("rejects duplicate level names outside the ignored id", async () => {
+    const db = {
+      managementLevel: {
+        findUnique: vi.fn().mockResolvedValue({ id: "level_existing", name: "Senior Team Lead" }),
+      },
+    } as never;
+
+    await expect(assertManagementLevelNameAvailable(db, "Senior Team Lead")).rejects.toBeInstanceOf(TRPCError);
+  });
+
+  it("builds create and sparse update payloads", () => {
+    expect(buildManagementLevelGroupCreateData({
+      name: "Team Leads",
+      targetPercentage: 0.72,
+      sortOrder: 10,
+    })).toEqual({
+      name: "Team Leads",
+      targetPercentage: 0.72,
+      sortOrder: 10,
+    });
+
+    expect(buildManagementLevelGroupUpdateData({
+      targetPercentage: 0.8,
+    })).toEqual({
+      targetPercentage: 0.8,
+    });
+
+    expect(buildManagementLevelCreateData({
+      name: "Senior Team Lead",
+      groupId: "group_1",
+    })).toEqual({
+      name: "Senior Team Lead",
+      groupId: "group_1",
+    });
+
+    expect(buildManagementLevelUpdateData({
+      groupId: "group_2",
+    })).toEqual({
+      groupId: "group_2",
+    });
+  });
+
+  it("rejects deletion when a level is still assigned", () => {
+    expect(() => assertManagementLevelDeletable({
+      _count: { resources: 2 },
+    })).toThrow(TRPCError);
+  });
+});
diff --git a/packages/api/src/router/management-level-support.ts b/packages/api/src/router/management-level-support.ts
new file mode 100644
index 0000000..8312033
--- /dev/null
+++ b/packages/api/src/router/management-level-support.ts
@@ -0,0 +1,100 @@
+import type { Prisma, PrismaClient } from "@capakraken/db";
+import {
+  CreateManagementLevelGroupSchema,
+  CreateManagementLevelSchema,
+  UpdateManagementLevelGroupSchema,
+  UpdateManagementLevelSchema,
+} from "@capakraken/shared";
+import { TRPCError } from "@trpc/server";
+import { z } from "zod";
+
+type ManagementLevelGroupDb = Pick<PrismaClient, "managementLevelGroup">;
+type ManagementLevelDb = Pick<PrismaClient, "managementLevel">;
+
+type ManagementLevelDeleteRecord = {
+  _count: {
+    resources: number;
+  };
+};
+
+type CreateManagementLevelGroupInput = z.infer<typeof CreateManagementLevelGroupSchema>;
+type UpdateManagementLevelGroupInput = z.infer<typeof UpdateManagementLevelGroupSchema>;
+type CreateManagementLevelInput = z.infer<typeof CreateManagementLevelSchema>;
+type UpdateManagementLevelInput = z.infer<typeof UpdateManagementLevelSchema>;
+
+export async function assertManagementLevelGroupNameAvailable(
+  db: ManagementLevelGroupDb,
+  name: string,
+  ignoreId?: string,
+): Promise<void> {
+  const existing = await db.managementLevelGroup.findUnique({ where: { name } });
+  if (existing && existing.id !== ignoreId) {
+    throw new TRPCError({
+      code: "CONFLICT",
+      message: `Group "${name}" already exists`,
+    });
+  }
+}
+
+export async function assertManagementLevelNameAvailable(
+  db: ManagementLevelDb,
+  name: string,
+  ignoreId?: string,
+): Promise<void> {
+  const existing = await db.managementLevel.findUnique({ where: { name } });
+  if (existing && existing.id !== ignoreId) {
+    throw new TRPCError({
+      code: "CONFLICT",
+      message: `Level "${name}" already exists`,
+    });
+  }
+}
+
+export function buildManagementLevelGroupCreateData(
+  input: CreateManagementLevelGroupInput,
+): Prisma.ManagementLevelGroupUncheckedCreateInput {
+  return {
+    name: input.name,
+    targetPercentage: input.targetPercentage,
+    sortOrder: input.sortOrder,
+  };
+}
+
+export function buildManagementLevelGroupUpdateData(
+  input: UpdateManagementLevelGroupInput,
+): Prisma.ManagementLevelGroupUncheckedUpdateInput {
+  return {
+    ...(input.name !== undefined ? { name: input.name } : {}),
+    ...(input.targetPercentage !== undefined ? { targetPercentage: input.targetPercentage } : {}),
+    ...(input.sortOrder !== undefined ? { sortOrder: input.sortOrder } : {}),
+  };
+}
+
+export function buildManagementLevelCreateData(
+  input: CreateManagementLevelInput,
+): Prisma.ManagementLevelUncheckedCreateInput {
+  return {
+    name: input.name,
+    groupId: input.groupId,
+  };
+}
+
+export function buildManagementLevelUpdateData(
+  input: UpdateManagementLevelInput,
+): Prisma.ManagementLevelUncheckedUpdateInput {
+  return {
+    ...(input.name !== undefined ? { name: input.name } : {}),
+    ...(input.groupId !== undefined ? { groupId: input.groupId } : {}),
+  };
+}
+
+export function assertManagementLevelDeletable(
+  level: ManagementLevelDeleteRecord,
+): void {
+  if (level._count.resources > 0) {
+    throw new TRPCError({
+      code: "PRECONDITION_FAILED",
+      message: `Cannot delete level assigned to ${level._count.resources} resource(s)`,
+    });
+  }
+}
diff --git a/packages/api/src/router/management-level.ts b/packages/api/src/router/management-level.ts
index 4f79340..14b35a3 100644
--- a/packages/api/src/router/management-level.ts
+++ b/packages/api/src/router/management-level.ts
@@ -4,11 +4,19 @@ import {
   UpdateManagementLevelGroupSchema,
   UpdateManagementLevelSchema,
 } from "@capakraken/shared";
-import { TRPCError } from "@trpc/server";
 import { z } from "zod";
 import { findUniqueOrThrow } from "../db/helpers.js";
 import { createAuditEntry } from "../lib/audit.js";
 import { adminProcedure, createTRPCRouter, planningReadProcedure } from "../trpc.js";
+import {
+  assertManagementLevelDeletable,
+  assertManagementLevelGroupNameAvailable,
+  assertManagementLevelNameAvailable,
+  buildManagementLevelCreateData,
+  buildManagementLevelGroupCreateData,
+  buildManagementLevelGroupUpdateData,
+  buildManagementLevelUpdateData,
+} from "./management-level-support.js";
 
 export const managementLevelRouter = createTRPCRouter({
   // ─── Groups ─────────────────────────────────────────────
@@ -39,16 +47,9 @@ export const managementLevelRouter = createTRPCRouter({
   createGroup: adminProcedure
     .input(CreateManagementLevelGroupSchema)
     .mutation(async ({ ctx, input }) => {
-      const existing = await ctx.db.managementLevelGroup.findUnique({ where: { name: input.name } });
-      if (existing) {
-        throw new TRPCError({ code: "CONFLICT", message: `Group "${input.name}" already exists` });
-      }
+      await assertManagementLevelGroupNameAvailable(ctx.db, input.name);
       const created = await ctx.db.managementLevelGroup.create({
-        data: {
-          name: input.name,
-          targetPercentage: input.targetPercentage,
-          sortOrder: input.sortOrder,
-        },
+        data: buildManagementLevelGroupCreateData(input),
         include: { levels: true },
       });
 
@@ -75,21 +76,14 @@ export const managementLevelRouter = createTRPCRouter({
       );
 
       if (input.data.name && input.data.name !== existing.name) {
-        const conflict = await ctx.db.managementLevelGroup.findUnique({ where: { name: input.data.name } });
-        if (conflict) {
-          throw new TRPCError({ code: "CONFLICT", message: `Group "${input.data.name}" already exists` });
-        }
+        await assertManagementLevelGroupNameAvailable(ctx.db, input.data.name, existing.id);
       }
 
       const before = existing as unknown as Record<string, unknown>;
 
       const updated = await ctx.db.managementLevelGroup.update({
         where: { id: input.id },
-        data: {
-          ...(input.data.name !== undefined ? { name: input.data.name } : {}),
-          ...(input.data.targetPercentage !== undefined ? { targetPercentage: input.data.targetPercentage } : {}),
-          ...(input.data.sortOrder !== undefined ? { sortOrder: input.data.sortOrder } : {}),
-        },
+        data: buildManagementLevelGroupUpdateData(input.data),
         include: { levels: true },
       });
 
@@ -118,13 +112,10 @@ export const managementLevelRouter = createTRPCRouter({
         "Group",
       );
 
-      const existing = await ctx.db.managementLevel.findUnique({ where: { name: input.name } });
-      if (existing) {
-        throw new TRPCError({ code: "CONFLICT", message: `Level "${input.name}" already exists` });
-      }
+      await assertManagementLevelNameAvailable(ctx.db, input.name);
 
       const created = await ctx.db.managementLevel.create({
-        data: { name: input.name, groupId: input.groupId },
+        data: buildManagementLevelCreateData(input),
       });
 
       void createAuditEntry({
@@ -150,20 +141,14 @@ export const managementLevelRouter = createTRPCRouter({
       );
 
       if (input.data.name && input.data.name !== existing.name) {
-        const conflict = await ctx.db.managementLevel.findUnique({ where: { name: input.data.name } });
-        if (conflict) {
-          throw new TRPCError({ code: "CONFLICT", message: `Level "${input.data.name}" already exists` });
-        }
+        await assertManagementLevelNameAvailable(ctx.db, input.data.name, existing.id);
       }
 
       const before = existing as unknown as Record<string, unknown>;
 
       const updated = await ctx.db.managementLevel.update({
         where: { id: input.id },
-        data: {
-          ...(input.data.name !== undefined ? { name: input.data.name } : {}),
-          ...(input.data.groupId !== undefined ? { groupId: input.data.groupId } : {}),
-        },
+        data: buildManagementLevelUpdateData(input.data),
       });
 
       void createAuditEntry({
@@ -191,12 +176,7 @@ export const managementLevelRouter = createTRPCRouter({
         }),
         "Level",
       );
-      if (level._count.resources > 0) {
-        throw new TRPCError({
-          code: "PRECONDITION_FAILED",
-          message: `Cannot delete level assigned to ${level._count.resources} resource(s)`,
-        });
-      }
+      assertManagementLevelDeletable(level);
       await ctx.db.managementLevel.delete({ where: { id: input.id } });
 
       void createAuditEntry({