Google Calendar sync not working with interview scheduling: causes and fixes

What the symptom means

If Google Calendar sync is not working with your interview scheduling, the two calendars have stopped agreeing. In ATS Mako, calendar sync keeps availability accurate in both directions. A slot booked elsewhere should not stay open for a candidate to double-book. Every booked interview should land on a shared calendar so recruiters, hiring managers and candidates work from the same source of truth.

A sync problem usually shows up in one of two directions. Figure out which one you have before you change anything.

Likely causes

Most Google Calendar sync issues in recruiting come down to a short list of causes.

• Access was never approved. When someone asks to subscribe to a calendar, Google requires the owner to approve the request before access is granted.
• The calendar is hidden. In Google Calendar, a calendar can be unchecked under "Other calendars," which hides it from view even though it still exists.
• The setup was attempted on a phone. Google does not allow subscribing to a new calendar from the Google Calendar app on Android, iPhone or iPad. It has to be done in a computer web browser.
• Authorization lapsed. Google's error guidance tells apps to send the user back through the OAuth sign-in flow when credentials stop working.
• The interviewer is not the event organizer. Google only lets the organizer change shared event properties, so an edit made against another person's copy can fail.
• Too many changes at once. Google limits how fast requests can be made per calendar, so a large burst of edits can be slowed down.
• A full resync is running. Google sometimes invalidates sync tokens, which forces a full resync before changes catch up.
• Too many subscribed calendars. Google notes that subscribing to a very large number of calendars can cause performance issues when browsing.

Fix steps

1. 1 Pick one test case Choose a single interview that did not sync. Note the candidate, interviewer, time and which direction failed. One clear example makes every step below faster.
2. 2 Open Google Calendar on a computer Use a web browser, not the mobile app. Subscribing to a calendar is not possible in the Google Calendar app for Android, iPhone or iPad.
3. 3 Check the calendar is visible On the left, under "Other calendars," make sure the interviewer's calendar is checked. An unchecked calendar is hidden, which can make a synced interview look missing.
4. 4 Confirm access was approved If the calendar belongs to someone else, ask the owner to check for an access request email and approve it. Access does not start until they do.
5. 5 Check who organizes the event Open the interview in Google Calendar and see who the organizer is. Only the organizer can change shared event properties, so updates from someone else's copy may not apply.
6. 6 Pause repeated edits If you just used bulk event updates to shift a batch of interviews, give sync time to finish before editing again. Repeating the same change can add to request limits and delay the result.
7. 7 Re-authorize if access looks broken If events stopped syncing for a specific person all at once, their calendar authorization may have lapsed. Contact support to get the connection re-authorized rather than guessing at settings.

Confirm it worked

Run a quick test in both directions before you tell the team it is fixed.

1. Add a busy block to the interviewer's Google Calendar. Open the candidate self-scheduling link and confirm that time is no longer offered.
2. Book a test interview through the self-scheduling link. Confirm it appears on the interviewer's Google Calendar and on the shared calendar in ATS Mako.
3. Reschedule the test booking. Confirm the old time clears and the new time shows in both places.
4. Check that the automated confirmation and reminder went out for the test booking, then cancel it.

If you want a refresher on how booking links, preset durations and reminders fit together, see the overview of interview scheduling and the shared calendar. For reminder and follow-up sequences around interviews, the page on automated engagement workflows covers the options.

When to contact support

Contact support if any of these apply:

• The test still fails after every fix step.
• Several recruiters or interviewers stopped syncing at the same time.
• You see an error such as "Sync token is no longer valid, a full sync is required." or "Shared properties can only be changed by the organizer of the event."
• Interviews you deleted keep reappearing or deletions fail.

Affected user(s):
Interviewer's Google account email:
Direction that failed (Google to scheduler, or scheduler to Google):
Example interview (candidate, date, time):
When it last worked:
Steps already tried:
Exact error text, if any: