My organisation blocks the connection

In many companies — especially law firms, consultancies and enterprises — IT blocks third-party app connections across the board. The good news: there’s always a way. This page shows all three — fastest first.

How do I recognise it?

• Microsoft 365: Right in the Microsoft sign-in you see “Need admin approval” — often with a field to send a justification to IT.
• Google Workspace: A message like “Access blocked: this app has not been verified by your administrator” / “App is blocked”.

If a different error appears instead (cancelled sign-in, wrong account), check Connection fails first.

Option A: iCal feed as a source — no IT, works now

Your calendar’s iCal address works without any OAuth approval — it’s a simple, read-only link that Outlook and Google offer themselves.

1. Copy the ICS URL — guide per provider.
2. Add it in Kalender Sync as an iCal feed source (Business plan).
3. Create a sync with the feed as the source — done.

Typical setup: the blocked company calendar becomes a source via feed and blocks your personal Google calendar — nobody double-books you anymore.

The honest trade-offs: the blocked calendar can only act as a source, not a target (feeds are read-only), and sync runs on a 5-minute cadence instead of near-instant.

Option B: Request IT approval — the clean way

An admin approves Kalender Sync once for the whole organisation; after that, everyone can connect normally. Effort for IT: about two minutes.

Everything your IT needs is collected at kalender-sync.de/it-admin: the Microsoft admin-consent link to click, the requested permissions in detail, a DPA under Art. 28 GDPR, sub-processors and hosting information for the compliance review.

A template for your request:

Subject: Approval for the app "Kalender-Sync" (2 minutes, Microsoft 365 / Google Workspace)

Hi IT team,

I'd like to use Kalender-Sync (kalender-sync.de) to sync calendar
availability in a GDPR-compliant way. When connecting my account,
I get "Need admin approval".

Could you approve the app for our organisation? All information
for your review — permissions, DPA under Art. 28 GDPR,
sub-processors, hosting in Germany — plus the admin-consent link
is here:

https://kalender-sync.de/it-admin/

Thanks!

For Google Workspace, approval happens in the Admin console (Security → API controls → third-party app access) — your IT will find the details on the IT admin page as well.

Option C: CalDAV — when Apple or Infomaniak is involved

If one of your calendars lives at iCloud or Infomaniak KSuite, no OAuth is needed at all: those connections use app passwords you create yourself — no IT required. Guides: Apple iCloud, KSuite.

Which option fits?

Your situation	Recommendation
Get going right away, the blocked calendar should block others	Option A — iCal feed as a source
IT is approachable, full functionality wanted	Option B — near-instant sync in both directions
Sync needs to write into the blocked calendar, IT won’t budge	Currently only Option B; an iCal export from Kalender Sync is planned → Known limitations
iCloud/KSuite calendar involved	Option C — app password instead of OAuth

Still stuck? Contact us — blocked organisations are a topic we’re happy to help with personally.