diff --git a/lib/reducers/primary-identity-public-key-reducer.js b/lib/reducers/primary-identity-public-key-reducer.js
new file mode 100644
--- /dev/null
+++ b/lib/reducers/primary-identity-public-key-reducer.js
@@ -0,0 +1,25 @@
+// @flow
+
+import {
+  logOutActionTypes,
+  deleteAccountActionTypes,
+} from '../actions/user-actions.js';
+import type { BaseAction } from '../types/redux-types.js';
+import { setNewSessionActionType } from '../utils/action-utils.js';
+
+const setPrimaryIdentityPublicKey = 'SET_PRIMARY_IDENTITY_PUBLIC_KEY';
+export default function reducePrimaryIdentityPublicKey(
+  state: ?string,
+  action: BaseAction,
+): ?string {
+  if (action.type === setPrimaryIdentityPublicKey) {
+    return action.payload;
+  } else if (
+    action.type === logOutActionTypes.success ||
+    action.type === deleteAccountActionTypes.success ||
+    action.type === setNewSessionActionType
+  ) {
+    return null;
+  }
+  return state;
+}
diff --git a/lib/types/redux-types.js b/lib/types/redux-types.js
--- a/lib/types/redux-types.js
+++ b/lib/types/redux-types.js
@@ -911,7 +911,8 @@
       +error: true,
       +payload: Error,
       +loadingInfo: LoadingInfo,
-    };
+    }
+  | { +type: 'SET_PRIMARY_IDENTITY_PUBLIC_KEY', payload: ?string };
 
 export type ActionPayload = ?(Object | Array<*> | $ReadOnlyArray<*> | string);
 export type SuperAction = {