How to sync two Outlook calendars from different accounts

Quick answer: Seeing two Outlook calendars in one app and keeping copies in both accounts are different jobs. Use a combined view when you only need to check both calendars yourself. To put commitments into the calendar colleagues schedule against, choose a permitted one-way copy or a two-way Mirror between writable calendars.

Choose the result before connecting accountsCopy Anchor Link

For a combined view, Microsoft explains working with multiple calendars in Outlook on the web. That view does not create an event copy in another mailbox.

Microsoft documents adding a personal account to work availability. That option connects one personal Google or Outlook.com account, includes its primary-calendar availability, and presents personal events without title or location in the Scheduling Assistant. It is not a general method for mirroring two company mailboxes. Check whether your account and employer permit it.

Check the two Microsoft identitiesCopy Anchor Link

Open each account's calendar in Outlook first. A work identity that can sign in but has no usable Exchange mailbox may have no calendars to connect. The accounts can be personal and work, or two permitted work accounts; each organization controls its own consent policy.

If you see “Need admin approval”, ask that organization's administrator to review the workspace access instructions. Connecting a personal intermediary or switching the sync direction does not grant access to the restricted mailbox.

For a colleague's calendar, confirm the calendar-level access separately. Being able to view it in Outlook does not prove you can write to it. Use the shared-calendar guide linked below.

Connect both accounts to one SYNCDATE loginCopy Anchor Link

Open Accounts in the dashboard and connect the first Microsoft account, then the second. Check the identity on each Microsoft consent screen. If Microsoft keeps choosing the first account, sign out of it or use a private browser window before connecting the next one.

The SYNCDATE login is separate from these calendar connections. Keep both connected accounts under the same SYNCDATE login for this arrangement.

Build a Mirror or choose a one-way recipeCopy Anchor Link

For copies in both accounts, create one sync, select Mirror, and add one writable calendar from each Microsoft account. Review direction, appearance, filters and date window before starting. A Mirror copies originals from either calendar to the other; it does not require a separate reverse sync.

For a one-way personal-to-work arrangement, start with the personal-to-work recipe. Its masked titles, omitted descriptions, locations and guests are a starting configuration you still need to review. It preserves source availability: a Free original remains Free, even if the copy is titled Busy.

The Google–Outlook recipe is for a Google/Microsoft pair. For two Microsoft accounts, choose the calendars in the composer rather than treating a provider-specific preset as an Outlook-only setup.

Decide what another account receivesCopy Anchor Link

Title and Free or busy are separate settings. Pick Busy under Title to mask the event name. Pick Same as original to retain the original availability, or Always busy when every eligible copied event must block time. Leave descriptions, locations and guests out if those details should not enter the other account.

For different appearance in each destination, review appearance for each destination and their Pro requirement. A Private flag is not the same as omitting information: do not copy a confidential title and assume the flag prevents every administrator from accessing it.

Free covers two accounts, two calendars and one sync with a 30-day forward window. Existing usage counts toward those limits. More accounts or calendars, a longer window, or per-calendar appearance can require a paid plan. Check current prices for the arrangement you need.

Verify creation, edits, deletion and availabilityCopy Anchor Link

Use empty test calendars where possible. Starting a sync can copy existing eligible events; review access and appearance first.

1. Create a nonrecurring Busy event called “Outlook sync check” in the first selected calendar, inside the sync window and with no guests or sensitive notes.
2. Open the actual second calendar and inspect the copy's time, title, details and Free/Busy status. Seeing both originals in an app overlay is not this check.
3. Move the original event and verify the corresponding copy changes. Delete the original test event and verify cleanup.
4. Repeat from the other account if you chose Mirror. For a Push, events created in the destination do not flow back to the source.
5. Test a separate Free original with Same as original selected. Confirm its destination remains Free even if its title says Busy.
6. Check the Scheduling Assistant or booking tool that people use to schedule with you. Confirm it checks the calendar receiving the copies.

There is a delay between a change and its arrival in another system. Google and Outlook changes usually reach the other calendar in under a minute; CalDAV calendars are checked about every 15 minutes; iCal feeds on a schedule. Provider notifications, processing, limits and retries can add to that. Verify the outcome you need before relying on it for a critical slot.

Add a third work or client account deliberatelyCopy Anchor Link

If every account needs to receive originals from every other account, use one supported multi-calendar Mirror. Three or four calendars in that Mirror require Plus; five require Pro. Each destination must be writable and each organization's consent policy still applies. Review what client details may enter every destination before starting.

If you only need one calendar to collect the others, choose one Push with several sources and a hub destination. Plus allows up to 10 calendars in a Push and Pro up to 20, within the plan's account and total-calendar limits. That hub does not put the other clients' commitments back into each source calendar. The client-hub recipe explains the distinction.

Copies made by one sync do not relay through another. Separate two-calendar syncs through an intermediary cannot establish shared availability across all accounts. The multi-account Mirror recipe gives a starting configuration to review; verify each destination and scheduling view yourself. We have not established a universal cross-tenant success result from the instructions alone.

If Outlook now shows both originals and copies together, choose a planning view before treating that as duplicate data. For Busy one way and details the other, review asymmetric appearance.

If the two calendars still disagreeCopy Anchor Link

Check the account identities, selected calendars, write permissions, direction, filters and date window. If another sync service already writes to this pair, review its cleanup policy and stop the old writer before switching production calendars. Running both on the same pair can create duplicates.

For three or more company accounts, choose one supported multi-calendar Mirror or a one-way collection into a hub. Separate syncs do not relay their copies through an intermediary calendar. Read supported limits before extending the arrangement.

If the observed copy differs from your settings, contact support with the sync ID, event time and observed difference. Keep credentials, secret calendar URLs and unnecessary event details out of the message.

Related

Connecting a second or third account

How to add another Google, Microsoft or iCloud login, what happens when one is already connected, and what disconnecting does to your copies.

Connect a shared Outlook calendar

How Microsoft consent and calendar sharing work together, and when a shared calendar can be a sync source or target.

Direction: one-way or two-way

Push copies one way and never touches the source. Mirror goes both ways. How to tell which one you need, and what changing it later deletes.

Appearance: how copied events look

Every setting that decides what a copy looks like when it lands: title, availability, privacy, colour, guests and reminders.

Plans and limits

The five numbers that limit a setup, what each one means, and which one actually stops people.

Show Busy to clients, full details to you

Work shows Busy, personal keeps every detail. A rule per calendar needs Pro; a rule by source calendar needs Plus.

Mirror or Push: which one do you need

Push feeds one calendar from another and never touches the source. Mirror goes both ways. How to choose, and what switching later deletes.

Personal → Work, shown as Busy

Your work calendar shows "Busy" when you have a personal appointment, and nobody at work sees what it is. Nothing is written to your personal calendar.