diff --git a/static/js/settings_invites.js b/static/js/settings_invites.js
index 74b03ae91d..a2024cec72 100644
--- a/static/js/settings_invites.js
+++ b/static/js/settings_invites.js
@@ -48,12 +48,14 @@ function populate_invites(invites_data) {
             item.is_admin = page_params.is_admin;
             item.disable_buttons = item.invited_as === settings_config.user_role_values.owner.code
                 && !page_params.is_owner;
+            item.referrer_email = people.get_by_user_id(item.invited_by_user_id).email;
             return render_admin_invites_list({ invite: item });
         },
         filter: {
             element: invites_table.closest(".settings-section").find(".search"),
             predicate: function (item, value) {
-                const referrer_email_matched = item.ref.toLowerCase().includes(value);
+                const referrer_email = people.get_by_user_id(item.invited_by_user_id).email;
+                const referrer_email_matched = referrer_email.toLowerCase().includes(value);
                 if (item.is_multiuse) {
                     return referrer_email_matched;
                 }
diff --git a/static/templates/admin_invites_list.hbs b/static/templates/admin_invites_list.hbs
index 2835573c09..b059d69971 100644
--- a/static/templates/admin_invites_list.hbs
+++ b/static/templates/admin_invites_list.hbs
@@ -13,7 +13,7 @@
     </td>
     {{#if is_admin}}
     <td>
-        <span class="referred_by">{{ref}}</span>
+        <span class="referred_by">{{referrer_email}}</span>
     </td>
     {{/if}}
     <td>
diff --git a/templates/zerver/api/changelog.md b/templates/zerver/api/changelog.md
index f84c429247..8e61ff297b 100644
--- a/templates/zerver/api/changelog.md
+++ b/templates/zerver/api/changelog.md
@@ -12,9 +12,15 @@ below features are supported.
 
 **Feature level 22**
 
-* 'GET /attachments': Rename `name` to `date_sent` for clearer meaning
-   and change the data types of the new `date_sent` and `create_time`
-   to integer (previously the implementation could send floats).
+* `GET /attachments`: The date when a message using the attachment was
+  sent is now correctly encoded as `date_sent`, replacing the
+  confusingly named `name` field.  The `date_sent` and `create_time`
+  fields of attachment objects are now encoded as integers;
+  (previously the implementation could send floats incorrectly
+  suggesting that microsecond precision is relevant).
+* `GET /invites`: Now encodes the user ID of the person who created
+   the invitation as `invited_by_user_id`, replacing the previous
+   `ref` field (which had that user's Zulip display email address).
 
 **Feature level 21**
 
diff --git a/version.py b/version.py
index 699ee335b0..06d110658c 100644
--- a/version.py
+++ b/version.py
@@ -29,7 +29,7 @@ DESKTOP_WARNING_VERSION = "5.2.0"
 #
 # Changes should be accompanied by documentation explaining what the
 # new level means in templates/zerver/api/changelog.md.
-API_FEATURE_LEVEL = 21
+API_FEATURE_LEVEL = 22
 
 # Bump the minor PROVISION_VERSION to indicate that folks should provision
 # only when going from an old version of the code to a newer version. Bump
diff --git a/zerver/lib/actions.py b/zerver/lib/actions.py
index 4864c69b4e..2fde7f3031 100644
--- a/zerver/lib/actions.py
+++ b/zerver/lib/actions.py
@@ -5282,7 +5282,7 @@ def do_get_user_invites(user_profile: UserProfile) -> List[Dict[str, Any]]:
 
     for invitee in prereg_users:
         invites.append(dict(email=invitee.email,
-                            ref=invitee.referred_by.email,
+                            invited_by_user_id=invitee.referred_by.id,
                             invited=datetime_to_timestamp(invitee.invited_at),
                             id=invitee.id,
                             invited_as=invitee.invited_as,
@@ -5298,7 +5298,7 @@ def do_get_user_invites(user_profile: UserProfile) -> List[Dict[str, Any]]:
                                                              date_sent__gte=lowest_datetime)
     for confirmation_obj in multiuse_confirmation_objs:
         invite = confirmation_obj.content_object
-        invites.append(dict(ref=invite.referred_by.email,
+        invites.append(dict(invited_by_user_id=invite.referred_by.id,
                             invited=datetime_to_timestamp(confirmation_obj.date_sent),
                             id=invite.id,
                             link_url=confirmation_url(confirmation_obj.confirmation_key,
diff --git a/zerver/tests/test_signup.py b/zerver/tests/test_signup.py
index c6b2118623..6c6388b332 100644
--- a/zerver/tests/test_signup.py
+++ b/zerver/tests/test_signup.py
@@ -1664,12 +1664,13 @@ class InvitationsTestCase(InviteUserBase):
 
         result = self.client_get("/json/invites")
         self.assertEqual(result.status_code, 200)
-        self.assert_in_success_response(
-            ["TestOne@zulip.com", hamlet.email],
-            result)
-        self.assert_not_in_success_response(
-            ["TestTwo@zulip.com", "TestThree@zulip.com", "othello@zulip.com", othello.email],
-            result)
+        invites = ujson.loads(result.content)["invites"]
+        self.assertEqual(len(invites), 2)
+
+        self.assertFalse(invites[0]["is_multiuse"])
+        self.assertEqual(invites[0]["email"], "TestOne@zulip.com")
+        self.assertTrue(invites[1]["is_multiuse"])
+        self.assertEqual(invites[1]["invited_by_user_id"], hamlet.id)
 
     def test_successful_delete_invitation(self) -> None:
         """