diff --git a/packages/calling/src/SDKConnector/types.ts b/packages/calling/src/SDKConnector/types.ts
index 05e80797a1d..840a3f872a2 100644
--- a/packages/calling/src/SDKConnector/types.ts
+++ b/packages/calling/src/SDKConnector/types.ts
@@ -26,6 +26,29 @@ export type Model = {
   };
 };
 
+export type WDMDevice = {
+  url: string;
+  userId: string;
+  orgId: string;
+  version: string;
+  callingBehavior: string;
+  registered?: boolean;
+  webSocketUrl?: string;
+  register?: () => Promise<unknown>;
+  refresh?: () => Promise<unknown>;
+  /** WDM / device-registration settings (e.g. `webrtc-calling-over-ws`). */
+  settings?: Record<string, {value?: boolean} | undefined>;
+  features: {
+    developer: {
+      models: Model[];
+      get: (key: string) => {value: boolean} | undefined;
+    };
+    entitlement: {
+      models: Model[];
+    };
+  };
+};
+
 export type ServiceCatalog = {
   serviceGroups: {
     // cSpell:disable
@@ -99,28 +122,7 @@ export interface WebexSDK {
       updateFeature?: (featureToggle: unknown) => void;
     };
     calendar: unknown;
-    device: {
-      url: string;
-      userId: string;
-      orgId: string;
-      version: string;
-      callingBehavior: string;
-      registered?: boolean;
-      webSocketUrl?: string;
-      register?: () => Promise<unknown>;
-      refresh?: () => Promise<unknown>;
-      /** WDM / device-registration settings (e.g. `webrtc-calling-over-ws`). */
-      settings?: Record<string, {value?: boolean} | undefined>;
-      features: {
-        developer: {
-          models: Model[];
-          get: (key: string) => {value: boolean} | undefined;
-        };
-        entitlement: {
-          models: Model[];
-        };
-      };
-    };
+    device: WDMDevice;
     encryption: {
       decryptText: (encryptionKeyUrl: string, encryptedData?: string) => Promise<string>;
       encryptText: (encryptionKeyUrl: string, text?: string) => Promise<string>;
diff --git a/packages/calling/src/common/Utils.test.ts b/packages/calling/src/common/Utils.test.ts
index 044938c324e..a88fa7b0840 100644
--- a/packages/calling/src/common/Utils.test.ts
+++ b/packages/calling/src/common/Utils.test.ts
@@ -51,6 +51,8 @@ import {
   modifySdpForIPv4,
   uploadLogs,
   handleCallingClientErrors,
+  resolveCallingBackend,
+  getCallingBackEnd,
 } from './Utils';
 import {
   getVoicemailListJsonWXC,
@@ -2081,3 +2083,88 @@ describe('uploadLogs', () => {
     );
   });
 });
+
+describe('resolveCallingBackend', () => {
+  const createDevice = (callingBehavior: string, entitlementKeys: string[]) => ({
+    url: 'https://wdm.example.com/devices/123',
+    userId: 'user-id',
+    orgId: 'org-id',
+    version: '1.0',
+    callingBehavior,
+    features: {
+      developer: {models: [], get: jest.fn()},
+      entitlement: {
+        models: entitlementKeys.map((key) => ({_values: {key}})),
+      },
+    },
+  });
+
+  it.each([
+    ['bc-sp-basic', CALLING_BACKEND.WXC],
+    ['bc-sp-standard', CALLING_BACKEND.WXC],
+  ])(
+    'returns WXC when callingBehavior is NATIVE_WEBEX_TEAMS_CALLING and entitlement is %s',
+    (entitlement, expected) => {
+      const device = createDevice('NATIVE_WEBEX_TEAMS_CALLING', [entitlement]);
+
+      expect(resolveCallingBackend(device)).toBe(expected);
+    }
+  );
+
+  it('returns BWRKS when callingBehavior is NATIVE_WEBEX_TEAMS_CALLING and entitlement is broadworks-connector', () => {
+    const device = createDevice('NATIVE_WEBEX_TEAMS_CALLING', ['broadworks-connector']);
+
+    expect(resolveCallingBackend(device)).toBe(CALLING_BACKEND.BWRKS);
+  });
+
+  it('returns UCM when callingBehavior is NATIVE_SIP_CALL_TO_UCM', () => {
+    const device = createDevice('NATIVE_SIP_CALL_TO_UCM', []);
+
+    expect(resolveCallingBackend(device)).toBe(CALLING_BACKEND.UCM);
+  });
+
+  it('returns INVALID when callingBehavior is unknown', () => {
+    const device = createDevice('UNKNOWN_BEHAVIOR', []);
+
+    expect(resolveCallingBackend(device)).toBe(CALLING_BACKEND.INVALID);
+  });
+
+  it('returns INVALID when callingBehavior is NATIVE_WEBEX_TEAMS_CALLING but no matching entitlement', () => {
+    const device = createDevice('NATIVE_WEBEX_TEAMS_CALLING', ['some-other-entitlement']);
+
+    expect(resolveCallingBackend(device)).toBe(CALLING_BACKEND.INVALID);
+  });
+
+  it('matches the first qualifying entitlement when multiple are present', () => {
+    const device = createDevice('NATIVE_WEBEX_TEAMS_CALLING', [
+      'broadworks-connector',
+      'bc-sp-basic',
+    ]);
+
+    expect(resolveCallingBackend(device)).toBe(CALLING_BACKEND.BWRKS);
+  });
+});
+
+describe('getCallingBackEnd', () => {
+  it('passes webex.internal.device to resolveCallingBackend and returns its result', () => {
+    const device = {
+      url: 'https://wdm.example.com/devices/123',
+      userId: 'user-id',
+      orgId: 'org-id',
+      version: '1.0',
+      callingBehavior: 'NATIVE_SIP_CALL_TO_UCM',
+      features: {
+        developer: {models: [], get: jest.fn()},
+        entitlement: {models: []},
+      },
+    };
+
+    const mockWebex = {internal: {device}} as any;
+
+    const result = getCallingBackEnd(mockWebex);
+
+    expect(result).toBe(resolveCallingBackend(device));
+    expect(resolveCallingBackend(device)).toBe(CALLING_BACKEND.UCM);
+    expect(result).toBe(CALLING_BACKEND.UCM);
+  });
+});
diff --git a/packages/calling/src/common/Utils.ts b/packages/calling/src/common/Utils.ts
index ecc05d5d492..801d2645e12 100644
--- a/packages/calling/src/common/Utils.ts
+++ b/packages/calling/src/common/Utils.ts
@@ -129,7 +129,7 @@ import {
   WEBEX_API_BTS,
   BW_XSI_ENDPOINT_VERSION_WITH_SLASH,
 } from './constants';
-import {Model, WebexSDK} from '../SDKConnector/types';
+import {Model, WDMDevice, WebexSDK} from '../SDKConnector/types';
 import SDKConnector from '../SDKConnector';
 import {CallSettingResponse} from '../CallSettings/types';
 import {ContactResponse} from '../Contacts/types';
@@ -1216,16 +1216,16 @@ export const waitForMsecs = (msec: number) =>
   });
 
 /**
- * Register calling backend.
+ * Determine the calling backend from the device object.
  *
- * @param webex -.
+ * @param device - The device object containing callingBehavior and entitlement features.
  * @returns CallingBackEnd.
  */
-export function getCallingBackEnd(webex: WebexSDK): CALLING_BACKEND {
-  const entModels: Model[] = webex.internal.device.features.entitlement.models;
+export function resolveCallingBackend(device: WDMDevice): CALLING_BACKEND {
+  const entModels: Model[] = device.features.entitlement.models;
   let callingBackend;
 
-  if (webex.internal.device.callingBehavior === NATIVE_WEBEX_TEAMS_CALLING) {
+  if (device.callingBehavior === NATIVE_WEBEX_TEAMS_CALLING) {
     for (let i = 0; i < entModels.length; i += 1) {
       if (
         entModels[i][VALUES][KEY] === ENTITLEMENT_BASIC ||
@@ -1238,13 +1238,23 @@ export function getCallingBackEnd(webex: WebexSDK): CALLING_BACKEND {
         break;
       }
     }
-  } else if (webex.internal.device.callingBehavior === NATIVE_SIP_CALL_TO_UCM) {
+  } else if (device.callingBehavior === NATIVE_SIP_CALL_TO_UCM) {
     callingBackend = CALLING_BACKEND.UCM;
   } else {
     callingBackend = CALLING_BACKEND.INVALID;
   }
 
-  return callingBackend as CALLING_BACKEND;
+  return callingBackend || CALLING_BACKEND.INVALID;
+}
+
+/**
+ * Register calling backend.
+ *
+ * @param webex -.
+ * @returns CallingBackEnd.
+ */
+export function getCallingBackEnd(webex: WebexSDK): CALLING_BACKEND {
+  return resolveCallingBackend(webex.internal.device);
 }
 
 /**
diff --git a/packages/calling/src/index.ts b/packages/calling/src/index.ts
index f450bca06c5..542eb4fb803 100644
--- a/packages/calling/src/index.ts
+++ b/packages/calling/src/index.ts
@@ -46,10 +46,13 @@ export {
   CallDetails,
   CallDirection,
   CallType,
+  CALLING_BACKEND,
   DisplayInformation,
   SORT,
   SORT_BY,
 } from './common/types';
+export {resolveCallingBackend} from './common/Utils';
+export {WDMDevice} from './SDKConnector/types';
 export {CallError, LineError} from './Errors';
 export {ICall, TransferType} from './CallingClient/calling/types';
 export {LOGGER} from './Logger/types';