diff --git a/lib/reducers/holder-reducer.js b/lib/reducers/holder-reducer.js
--- a/lib/reducers/holder-reducer.js
+++ b/lib/reducers/holder-reducer.js
@@ -1,5 +1,6 @@
 // @flow
 
+import { setClientDBStoreActionType } from '../actions/client-db-store-actions.js';
 import {
   processHoldersActionTypes,
   storeEstablishedHolderActionType,
@@ -17,6 +18,33 @@
   holderStatuses,
 } from '../types/holder-types.js';
 import type { BaseAction } from '../types/redux-types.js';
+import { getMessageForException } from '../utils/errors.js';
+import { assertObjectsAreEqual } from '../utils/objects.js';
+
+function assertHolderStoresAreEqual(
+  processedHolderStore: HolderStore,
+  expectedHolderStore: HolderStore,
+  location: string,
+  onStateDifference?: (message: string) => mixed,
+) {
+  try {
+    assertObjectsAreEqual(
+      processedHolderStore,
+      expectedHolderStore,
+      `HolderStore - ${location}`,
+    );
+  } catch (e) {
+    console.log(
+      'Error processing HolderStore ops',
+      processedHolderStore,
+      expectedHolderStore,
+    );
+    const message = `Error processing HolderStore ops ${
+      getMessageForException(e) ?? '{no exception message}'
+    }`;
+    onStateDifference?.(message);
+  }
+}
 
 const mapResultsToHolderItems: (
   status: HolderStatus,
@@ -41,6 +69,7 @@
 function reduceHolderStore(
   store: HolderStore,
   action: BaseAction,
+  onStateDifference?: (message: string) => mixed,
 ): ReduceHolderStoreResult {
   if (action.type === storeEstablishedHolderActionType) {
     const { blobHash, holder } = action.payload;
@@ -123,6 +152,20 @@
       holderStore: processHolderStoreOperations(store, holderStoreOperations),
       holderStoreOperations,
     };
+  } else if (action.type === setClientDBStoreActionType) {
+    const newHolderStore = action.payload.holders ?? {};
+
+    assertHolderStoresAreEqual(
+      { ...store, storedHolders: newHolderStore },
+      store,
+      action.type,
+      onStateDifference,
+    );
+
+    return {
+      holderStore: store,
+      holderStoreOperations: [],
+    };
   }
   return { holderStore: store, holderStoreOperations: [] };
 }
diff --git a/lib/reducers/master-reducer.js b/lib/reducers/master-reducer.js
--- a/lib/reducers/master-reducer.js
+++ b/lib/reducers/master-reducer.js
@@ -226,7 +226,11 @@
   const { store: queuedDMOperations, operations: dmOperationStoreOperations } =
     reduceDMOperationsQueue(state.queuedDMOperations, action);
 
-  const { holderStore } = reduceHolderStore(state.holderStore, action);
+  const { holderStore } = reduceHolderStore(
+    state.holderStore,
+    action,
+    onStateDifferenceForStaff,
+  );
 
   let storeOperations = {
     draftStoreOperations,