diff --git a/keyserver/src/creators/day-creator.js b/keyserver/src/creators/day-creator.js
--- a/keyserver/src/creators/day-creator.js
+++ b/keyserver/src/creators/day-creator.js
@@ -3,9 +3,11 @@
 import { ServerError } from 'lib/utils/errors.js';
 
 import createIDs from './id-creator.js';
-import { dbQuery, SQL } from '../database/database.js';
-
-const MYSQL_DUPLICATE_ENTRY_FOR_KEY_ERROR_CODE = 1062;
+import {
+  dbQuery,
+  MYSQL_DUPLICATE_ENTRY_FOR_KEY_ERROR_CODE,
+  SQL,
+} from '../database/database.js';
 
 async function fetchOrCreateDayID(
   threadID: string,
diff --git a/keyserver/src/creators/invite-link-creator.js b/keyserver/src/creators/invite-link-creator.js
--- a/keyserver/src/creators/invite-link-creator.js
+++ b/keyserver/src/creators/invite-link-creator.js
@@ -8,7 +8,11 @@
 import { ServerError } from 'lib/utils/errors.js';
 
 import createIDs from './id-creator.js';
-import { dbQuery, SQL } from '../database/database.js';
+import {
+  dbQuery,
+  MYSQL_DUPLICATE_ENTRY_FOR_KEY_ERROR_CODE,
+  SQL,
+} from '../database/database.js';
 import { fetchPrimaryInviteLinks } from '../fetchers/link-fetchers.js';
 import { fetchServerThreadInfos } from '../fetchers/thread-fetchers.js';
 import { checkThreadPermission } from '../fetchers/thread-permission-fetchers.js';
@@ -21,7 +25,7 @@
   request: CreateOrUpdatePublicLinkRequest,
 ): Promise<InviteLink> {
   if (!secretRegex.test(request.name)) {
-    throw new ServerError('invalid_parameters');
+    throw new ServerError('invalid_characters');
   }
 
   const permissionPromise = checkThreadPermission(
@@ -64,7 +68,10 @@
     `;
     try {
       await dbQuery(query);
-    } catch {
+    } catch (e) {
+      if (e.errno === MYSQL_DUPLICATE_ENTRY_FOR_KEY_ERROR_CODE) {
+        throw new ServerError('already_in_use');
+      }
       throw new ServerError('invalid_parameters');
     }
     return {
@@ -92,17 +99,21 @@
     )
   `;
   let result = null;
+  const deleteIDs = SQL`
+    DELETE FROM ids
+    WHERE id = ${id}
+  `;
   try {
     result = (await dbQuery(createLinkQuery))[0];
-  } catch {
+  } catch (e) {
+    await dbQuery(deleteIDs);
+    if (e.errno === MYSQL_DUPLICATE_ENTRY_FOR_KEY_ERROR_CODE) {
+      throw new ServerError('already_in_use');
+    }
     throw new ServerError('invalid_parameters');
   }
 
   if (result.affectedRows === 0) {
-    const deleteIDs = SQL`
-      DELETE FROM ids
-      WHERE id = ${id}
-    `;
     await dbQuery(deleteIDs);
     throw new ServerError('invalid_parameters');
   }
diff --git a/keyserver/src/database/database.js b/keyserver/src/database/database.js
--- a/keyserver/src/database/database.js
+++ b/keyserver/src/database/database.js
@@ -13,6 +13,8 @@
 
 const SQLStatement: SQLStatementType = SQL.SQLStatement;
 
+const MYSQL_DUPLICATE_ENTRY_FOR_KEY_ERROR_CODE = 1062;
+
 let migrationConnection;
 async function getMigrationConnection() {
   if (migrationConnection) {
@@ -203,4 +205,5 @@
   setConnectionContext,
   dbQuery,
   rawSQL,
+  MYSQL_DUPLICATE_ENTRY_FOR_KEY_ERROR_CODE,
 };
diff --git a/lib/shared/invite-links.js b/lib/shared/invite-links.js
new file mode 100644
--- /dev/null
+++ b/lib/shared/invite-links.js
@@ -0,0 +1,11 @@
+// @flow
+
+const inviteLinkErrorMessages = {
+  invalid_characters: 'Link cannot contain any spaces or special characters.',
+  offensive_words: 'No offensive or abusive words allowed.',
+  already_in_use: 'Public link URL already in use.',
+};
+
+const defaultErrorMessage = 'Unknown error.';
+
+export { inviteLinkErrorMessages, defaultErrorMessage };
diff --git a/native/invite-links/manage-public-link-screen.react.js b/native/invite-links/manage-public-link-screen.react.js
--- a/native/invite-links/manage-public-link-screen.react.js
+++ b/native/invite-links/manage-public-link-screen.react.js
@@ -6,6 +6,10 @@
 import { inviteLinkUrl } from 'lib/facts/links.js';
 import { useInviteLinksActions } from 'lib/hooks/invite-links.js';
 import { primaryInviteLinksSelector } from 'lib/selectors/invite-links-selectors.js';
+import {
+  defaultErrorMessage,
+  inviteLinkErrorMessages,
+} from 'lib/shared/invite-links.js';
 import type { ThreadInfo } from 'lib/types/thread-types.js';
 
 import Button from '../components/button.react.js';
@@ -40,7 +44,11 @@
 
   let errorComponent = null;
   if (error) {
-    errorComponent = <Text style={styles.error}>{error}</Text>;
+    errorComponent = (
+      <Text style={styles.error}>
+        {inviteLinkErrorMessages[error] ?? defaultErrorMessage}
+      </Text>
+    );
   }
 
   const onDisableButtonClick = React.useCallback(() => {
diff --git a/web/invite-links/manage/edit-link-modal.react.js b/web/invite-links/manage/edit-link-modal.react.js
--- a/web/invite-links/manage/edit-link-modal.react.js
+++ b/web/invite-links/manage/edit-link-modal.react.js
@@ -6,6 +6,10 @@
 import { useModalContext } from 'lib/components/modal-provider.react.js';
 import { inviteLinkUrl } from 'lib/facts/links.js';
 import { useInviteLinksActions } from 'lib/hooks/invite-links.js';
+import {
+  defaultErrorMessage,
+  inviteLinkErrorMessages,
+} from 'lib/shared/invite-links.js';
 import type { InviteLink } from 'lib/types/link-types.js';
 import type { ThreadInfo } from 'lib/types/thread-types.js';
 
@@ -40,7 +44,11 @@
 
   let errorComponent = null;
   if (error) {
-    errorComponent = <div className={css.errorContainer}>{error}</div>;
+    errorComponent = (
+      <div className={css.errorContainer}>
+        {inviteLinkErrorMessages[error] ?? defaultErrorMessage}
+      </div>
+    );
   }
 
   let disableLinkComponent = null;