diff --git a/common/api/core-backend.api.md b/common/api/core-backend.api.md
index 12a2a68cf69e..31d5e430ec7d 100644
--- a/common/api/core-backend.api.md
+++ b/common/api/core-backend.api.md
@@ -138,6 +138,7 @@ import { LineStyleProps } from '@itwin/core-common';
 import { LocalBriefcaseProps } from '@itwin/core-common';
 import { LocalDirName } from '@itwin/core-common';
 import { LocalFileName } from '@itwin/core-common';
+import { LockState as LockState_2 } from '@itwin/core-common';
 import { LogLevel } from '@itwin/core-bentley';
 import { LowAndHighXYZ } from '@itwin/core-geometry';
 import { MarkRequired } from '@itwin/core-bentley';
@@ -4049,15 +4050,15 @@ export interface LockControl {
 }
 
 // @internal (undocumented)
-export type LockMap = Map<Id64String, LockState>;
+export type LockMap = Map<Id64String, LockState_2>;
 
 // @beta
 export interface LockProps {
     readonly id: Id64String;
-    readonly state: LockState;
+    readonly state: LockState_2;
 }
 
-// @public
+// @public @deprecated
 export enum LockState {
     Exclusive = 2,
     None = 0,
@@ -4071,7 +4072,7 @@ export interface LockStatusExclusive {
     // (undocumented)
     lastCsIndex?: ChangesetIndex;
     // (undocumented)
-    state: LockState.Exclusive;
+    state: LockState_2.Exclusive;
 }
 
 // @internal
@@ -4081,7 +4082,7 @@ export interface LockStatusShared {
     // (undocumented)
     sharedBy: Set<BriefcaseId>;
     // (undocumented)
-    state: LockState.Shared;
+    state: LockState_2.Shared;
 }
 
 // @internal
diff --git a/common/api/core-common.api.md b/common/api/core-common.api.md
index e225dcd610cb..8409f5fe3a77 100644
--- a/common/api/core-common.api.md
+++ b/common/api/core-common.api.md
@@ -1640,6 +1640,20 @@ export namespace ConcreteEntityTypes {
     export function toBisCoreRootClassFullName(type: ConcreteEntityTypes): string;
 }
 
+// @public
+export interface ConflictingLock {
+    briefcaseIds: number[];
+    objectId: string;
+    state: LockState;
+}
+
+// @public
+export class ConflictingLocksError extends IModelError {
+    constructor(message: string, getMetaData?: LoggingMetaData, conflictingLocks?: ConflictingLock[]);
+    // (undocumented)
+    conflictingLocks?: ConflictingLock[];
+}
+
 // @alpha
 export enum ContentFlags {
     // (undocumented)
@@ -5533,6 +5547,13 @@ export interface Localization {
     unregisterNamespace(namespace: string): void;
 }
 
+// @public
+export enum LockState {
+    Exclusive = 2,
+    None = 0,
+    Shared = 1
+}
+
 export { LogFunction }
 
 export { LoggingMetaData }
diff --git a/common/api/summary/core-backend.exports.csv b/common/api/summary/core-backend.exports.csv
index 7e395cbb7aae..aabe2e2d1a44 100644
--- a/common/api/summary/core-backend.exports.csv
+++ b/common/api/summary/core-backend.exports.csv
@@ -266,6 +266,7 @@ beta;LockControl
 internal;LockMap = Map
 beta;LockProps
 public;LockState
+deprecated;LockState
 internal;LockStatusExclusive
 internal;LockStatusShared
 internal;MetaDataRegistry
diff --git a/common/api/summary/core-common.exports.csv b/common/api/summary/core-common.exports.csv
index f8d1b57d9496..8bfea9a2ddef 100644
--- a/common/api/summary/core-common.exports.csv
+++ b/common/api/summary/core-common.exports.csv
@@ -138,6 +138,8 @@ internal;computeTileChordTolerance(tile: TileMetadata, is3d: boolean, tileScreen
 alpha;ConcreteEntityTypes
 alpha;ConcreteEntityTypes
 internal;toBisCoreRootClassFullName(type: ConcreteEntityTypes): string
+public;ConflictingLock
+public;ConflictingLocksError 
 alpha;ContentFlags
 internal;class ContentIdProvider
 public;ContextRealityModel
@@ -460,6 +462,7 @@ public;LocalBriefcaseProps
 public;LocalDirName = string
 public;LocalFileName = string
 public;Localization
+public;LockState
 public;MapImageryProps
 public;MapImagerySettings
 public;MapLayerKey
diff --git a/common/changes/@itwin/core-backend/nick-conflictinglockserror_2024-06-17-17-47.json b/common/changes/@itwin/core-backend/nick-conflictinglockserror_2024-06-17-17-47.json
new file mode 100644
index 000000000000..99b35bb89b62
--- /dev/null
+++ b/common/changes/@itwin/core-backend/nick-conflictinglockserror_2024-06-17-17-47.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@itwin/core-backend",
+      "comment": "",
+      "type": "none"
+    }
+  ],
+  "packageName": "@itwin/core-backend"
+}
\ No newline at end of file
diff --git a/common/changes/@itwin/core-common/nick-conflictinglockserror_2024-06-17-17-47.json b/common/changes/@itwin/core-common/nick-conflictinglockserror_2024-06-17-17-47.json
new file mode 100644
index 000000000000..7c91fa5527dc
--- /dev/null
+++ b/common/changes/@itwin/core-common/nick-conflictinglockserror_2024-06-17-17-47.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@itwin/core-common",
+      "comment": "add ConflictingLocksError",
+      "type": "none"
+    }
+  ],
+  "packageName": "@itwin/core-common"
+}
\ No newline at end of file
diff --git a/core/backend/src/BackendHubAccess.ts b/core/backend/src/BackendHubAccess.ts
index 2d9527f27dda..1f1933cca413 100644
--- a/core/backend/src/BackendHubAccess.ts
+++ b/core/backend/src/BackendHubAccess.ts
@@ -9,25 +9,12 @@
 import { AccessToken, GuidString, Id64String, IModelHubStatus } from "@itwin/core-bentley";
 import {
   BriefcaseId, ChangesetFileProps, ChangesetIdWithIndex, ChangesetIndex, ChangesetIndexAndId, ChangesetIndexOrId, ChangesetProps, ChangesetRange,
-  IModelError, IModelVersion, LocalDirName, LocalFileName,
+  LockState as CommonLockState, IModelError, IModelVersion,
+  LocalDirName, LocalFileName,
 } from "@itwin/core-common";
 import { CheckpointProps, DownloadRequest, ProgressFunction } from "./CheckpointManager";
 import type { TokenArg } from "./IModelDb";
 
-/** The state of a lock.
- * @public
- */
-export enum LockState {
-  /** The element is not locked */
-  None = 0,
-  /** Holding a shared lock on an element blocks other users from acquiring the Exclusive lock it. More than one user may acquire the shared lock. */
-  Shared = 1,
-  /** A Lock that permits modifications to an element and blocks other users from making modifications to it.
-   * Holding an exclusive lock on an "owner" (a model or a parent element), implicitly exclusively locks all its members.
-   */
-  Exclusive = 2,
-}
-
 /** Exception thrown if lock cannot be acquired.
  * @beta
 */
@@ -43,6 +30,21 @@ export class LockConflict extends IModelError {
   }
 }
 
+/** The state of a lock. See [Acquiring locks on elements.]($docs/learning/backend/ConcurrencyControl.md#acquiring-locks-on-elements).
+ * @deprecated in 4.7 Use [LockState]($common)
+ * @public
+ */
+export enum LockState {
+  /** The element is not locked */
+  None = 0,
+  /** Holding a shared lock on an element blocks other users from acquiring the Exclusive lock it. More than one user may acquire the shared lock. */
+  Shared = 1,
+  /** A Lock that permits modifications to an element and blocks other users from making modifications to it.
+   * Holding an exclusive lock on an "owner" (a model or a parent element), implicitly exclusively locks all its members.
+   */
+  Exclusive = 2,
+}
+
 /**
  * The properties to access a V2 checkpoint through a daemon.
  * @internal
@@ -61,7 +63,7 @@ export interface V2CheckpointAccessProps {
 }
 
 /** @internal */
-export type LockMap = Map<Id64String, LockState>;
+export type LockMap = Map<Id64String, CommonLockState>;
 
 /**
  * The properties of a lock that may be obtained from a lock server.
@@ -71,7 +73,7 @@ export interface LockProps {
   /** The elementId for the lock */
   readonly id: Id64String;
   /** the lock state */
-  readonly state: LockState;
+  readonly state: CommonLockState;
 }
 
 /**
@@ -232,6 +234,7 @@ export interface BackendHubAccess {
   /**
    * acquire one or more locks. Throws if unsuccessful. If *any* lock cannot be obtained, no locks are acquired
    * @internal
+   * @throws ConflictingLocksError if one or more requested locks are held by other briefcases.
    */
   acquireLocks: (arg: BriefcaseDbArg, locks: LockMap) => Promise<void>;
 
diff --git a/core/backend/src/IModelDb.ts b/core/backend/src/IModelDb.ts
index 28aec807655e..750f78fcb9f9 100644
--- a/core/backend/src/IModelDb.ts
+++ b/core/backend/src/IModelDb.ts
@@ -167,6 +167,7 @@ export interface LockControl {
    * If any required lock is not available, this method throws an exception and *none* of the requested locks are acquired.
    * > Note: acquiring the exclusive lock on an element requires also obtaining a shared lock on all its owner elements. This method will
    * attempt to acquire all necessary locks for both sets of input ids.
+   * @throws ConflictingLocksError if one or more requested locks are held by other briefcases.
    */
   acquireLocks(arg: {
     /** if present, one or more elements to obtain shared lock */
diff --git a/core/backend/src/LocalHub.ts b/core/backend/src/LocalHub.ts
index 11344981299b..d3a6e57d4a51 100644
--- a/core/backend/src/LocalHub.ts
+++ b/core/backend/src/LocalHub.ts
@@ -7,9 +7,9 @@ import { join } from "path";
 import { DbResult, GuidString, Id64String, IModelHubStatus, IModelStatus, OpenMode } from "@itwin/core-bentley";
 import {
   BriefcaseId, BriefcaseIdValue, ChangesetFileProps, ChangesetId, ChangesetIdWithIndex, ChangesetIndex, ChangesetIndexOrId, ChangesetProps,
-  ChangesetRange, IModelError, LocalDirName, LocalFileName,
+  ChangesetRange, IModelError, LocalDirName, LocalFileName, LockState,
 } from "@itwin/core-common";
-import { LockConflict, LockMap, LockProps, LockState } from "./BackendHubAccess";
+import { LockConflict, LockMap, LockProps } from "./BackendHubAccess";
 import { BriefcaseManager } from "./BriefcaseManager";
 import { BriefcaseLocalValue, IModelDb, SnapshotDb } from "./IModelDb";
 import { IModelJsFs } from "./IModelJsFs";
diff --git a/core/backend/src/ServerBasedLocks.ts b/core/backend/src/ServerBasedLocks.ts
index 9de7a7437de2..0d4c79bafb05 100644
--- a/core/backend/src/ServerBasedLocks.ts
+++ b/core/backend/src/ServerBasedLocks.ts
@@ -8,8 +8,8 @@
  */
 
 import { DbResult, Id64, Id64Arg, Id64String, IModelStatus, OpenMode } from "@itwin/core-bentley";
-import { IModel, IModelError } from "@itwin/core-common";
-import { LockMap, LockState } from "./BackendHubAccess";
+import { IModel, IModelError, LockState } from "@itwin/core-common";
+import { LockMap } from "./BackendHubAccess";
 import { BriefcaseDb, LockControl } from "./IModelDb";
 import { IModelHost } from "./IModelHost";
 import { SQLiteDb } from "./SQLiteDb";
diff --git a/core/backend/src/test/standalone/HubMock.test.ts b/core/backend/src/test/standalone/HubMock.test.ts
index 1b6e37c7f2bc..37680dad5d85 100644
--- a/core/backend/src/test/standalone/HubMock.test.ts
+++ b/core/backend/src/test/standalone/HubMock.test.ts
@@ -6,8 +6,8 @@
 import { assert, expect } from "chai";
 import { join } from "path";
 import { AccessToken, Guid, Mutable } from "@itwin/core-bentley";
-import { ChangesetFileProps, ChangesetType } from "@itwin/core-common";
-import { LockProps, LockState } from "../../BackendHubAccess";
+import { ChangesetFileProps, ChangesetType, LockState } from "@itwin/core-common";
+import { LockProps } from "../../BackendHubAccess";
 import { BriefcaseManager } from "../../BriefcaseManager";
 import { IModelHost } from "../../IModelHost";
 import { IModelJsFs } from "../../IModelJsFs";
diff --git a/core/backend/src/test/standalone/IModelWrite.test.ts b/core/backend/src/test/standalone/IModelWrite.test.ts
index 0edd0ce8a2d7..e65d7842b79a 100644
--- a/core/backend/src/test/standalone/IModelWrite.test.ts
+++ b/core/backend/src/test/standalone/IModelWrite.test.ts
@@ -6,7 +6,7 @@
 import { AccessToken, DbResult, GuidString, Id64, Id64String } from "@itwin/core-bentley";
 import {
   Code, ColorDef,
-  GeometricElement2dProps, GeometryStreamProps, IModel, QueryRowFormat, RequestNewBriefcaseProps, SchemaState, SubCategoryAppearance,
+  GeometricElement2dProps, GeometryStreamProps, IModel, LockState, QueryRowFormat, RequestNewBriefcaseProps, SchemaState, SubCategoryAppearance,
 } from "@itwin/core-common";
 import { Arc3d, IModelJson, Point2d, Point3d } from "@itwin/core-geometry";
 import * as chai from "chai";
@@ -24,7 +24,7 @@ import {
   BriefcaseManager,
   ChannelControl,
   CodeService,
-  DefinitionModel, DictionaryModel, DocumentListModel, Drawing, DrawingGraphic, LockState, OpenBriefcaseArgs, SpatialCategory, Subject,
+  DefinitionModel, DictionaryModel, DocumentListModel, Drawing, DrawingGraphic, OpenBriefcaseArgs, SpatialCategory, Subject,
 } from "../../core-backend";
 import { IModelTestUtils, TestUserType } from "../IModelTestUtils";
 import { ServerBasedLocks } from "../../ServerBasedLocks";
diff --git a/core/backend/src/test/standalone/ServerBasedLocks.test.ts b/core/backend/src/test/standalone/ServerBasedLocks.test.ts
index b077fe058334..ed9ea4abc818 100644
--- a/core/backend/src/test/standalone/ServerBasedLocks.test.ts
+++ b/core/backend/src/test/standalone/ServerBasedLocks.test.ts
@@ -6,8 +6,7 @@
 import { assert, expect } from "chai";
 import { restore as sinonRestore, spy as sinonSpy } from "sinon";
 import { AccessToken, GuidString, Id64, Id64Arg } from "@itwin/core-bentley";
-import { Code, IModel, IModelError, LocalBriefcaseProps, PhysicalElementProps, RequestNewBriefcaseProps } from "@itwin/core-common";
-import { LockState } from "../../BackendHubAccess";
+import { Code, IModel, IModelError, LocalBriefcaseProps, LockState, PhysicalElementProps, RequestNewBriefcaseProps } from "@itwin/core-common";
 import { BriefcaseManager } from "../../BriefcaseManager";
 import { PhysicalObject } from "../../domains/GenericElements";
 import { PhysicalElement } from "../../Element";
diff --git a/core/common/src/IModelError.ts b/core/common/src/IModelError.ts
index 3d745e2e7bac..5dc30e6e3d0e 100644
--- a/core/common/src/IModelError.ts
+++ b/core/common/src/IModelError.ts
@@ -7,7 +7,7 @@
  */
 
 import {
-  BentleyError, BentleyStatus, BriefcaseStatus, ChangeSetStatus, DbResult, IModelStatus, LoggingMetaData, RepositoryStatus,
+  BentleyError, BentleyStatus, BriefcaseStatus, ChangeSetStatus, DbResult, IModelHubStatus, IModelStatus, LoggingMetaData, RepositoryStatus,
 } from "@itwin/core-bentley";
 
 export {
@@ -32,6 +32,50 @@ export class IModelError extends BentleyError {
   }
 }
 
+/** The state of a lock. See [Acquiring locks on elements.]($docs/learning/backend/ConcurrencyControl.md#acquiring-locks-on-elements).
+ * @public
+ */
+export enum LockState {
+  /** The element is not locked */
+  None = 0,
+  /** Holding a shared lock on an element blocks other users from acquiring the Exclusive lock it. More than one user may acquire the shared lock. */
+  Shared = 1,
+  /** A Lock that permits modifications to an element and blocks other users from making modifications to it.
+   * Holding an exclusive lock on an "owner" (a model or a parent element), implicitly exclusively locks all its members.
+   */
+  Exclusive = 2,
+}
+
+/** Detailed information about a particular object Lock that is causing the Lock update conflict.
+ * An example of a lock update conflict would be attempting to use [LockControl.acquireLocks]($backend) on an object that is already locked by another Briefcase.
+ * @public
+*/
+export interface ConflictingLock {
+  /** Id of the object that is causing conflict. */
+  objectId: string;
+  /**
+     * The level of conflicting lock. Possible values are {@link LockState.Shared}, {@link LockState.Exclusive}.
+     * See {@link LockState}.
+     */
+  state: LockState;
+  /** An array of Briefcase ids that hold this lock. */
+  briefcaseIds: number[];
+}
+
+/**
+ * An error raised when there is a lock conflict detected.
+ * Typically this error would be thrown by [LockControl.acquireLocks]($backend) when you are requesting a lock on an element that is already held by another briefcase.
+ * @public
+ */
+export class ConflictingLocksError extends IModelError {
+  public conflictingLocks?: ConflictingLock[];
+  constructor(message: string, getMetaData?: LoggingMetaData, conflictingLocks?: ConflictingLock[]) {
+    super(IModelHubStatus.LockOwnedByAnotherBriefcase, message, getMetaData);
+    this.conflictingLocks = conflictingLocks;
+  }
+
+}
+
 /** @public */
 export class ServerError extends IModelError {
   public constructor(errorNumber: number, message: string) {