Sync a Microsoft 365 calendar without admin approval

You tried to connect a work calendar and got a screen saying an administrator has to approve twocal first — usually worded “Need admin approval” or“Approval required”. That is your organisation’s policy on third-party apps. It is not specific to twocal, and it is not something we can switch off from our side.

There are two ways forward.

Option 1 — ask your admin to approve it

The better outcome if your IT team is responsive, because it gives you a full two-way connection with changes pushed through in seconds. Forward them the approval request Microsoft generated, and tell them which calendars you intend to sync. If they want detail on what twocal reads and writes before they decide, send them to [email protected] and we will answer them directly.

Plenty of admins never get around to it. If that is where you are, option 2 does not involve them at all.

Option 2 — publish the calendar as an ICS link

Outlook can publish one of your calendars as a subscription link. This is a setting on your own mailbox rather than an app authorisation, so it commonly works even when app consent is blocked.

1. Open Outlook on the web and click the settings gear (top right).
2. Go to Calendar → Shared calendars.
3. Under Publish a calendar, choose the calendar you want to sync.
4. Set the permission to Can view all details.
5. Click Publish.
6. Copy the ICS link. Outlook also offers an HTML link — that one will not work.
7. In twocal, add a calendar, pick ICS, and paste the link in.

What this gets you, and what it doesn’t

Worth being straight about the trade, because it is a real one.

• One direction only. A published feed is read-only by definition, so your work calendar can sync out to a personal calendar, and nothing can be written back in. Blocking your work commitments on a personal calendar works. Making personal commitments show as busy at work does not. twocal enforces this — an ICS calendar cannot be used in a two-way sync.
• Minutes, not seconds. A connected account pushes changes to us as they happen. A published feed has to be polled, and Microsoft regenerates it on its own schedule, so expect a lag of minutes on both sides of that.
• Treat the link as a secret. Anyone holding the URL can read the calendar you published, with no sign-in. Don’t paste it anywhere public. You can revoke it from the same settings screen at any time, which immediately breaks the sync.

If “Publish a calendar” isn’t there

Then your administrator has disabled calendar publishing as well as app consent, and there is no route around both. That one is genuinely a conversation with your IT team — and we are happy to be in it. Mail [email protected] and we will help you make the case.