Fantastical: how to decide what you need

If a work calendar in Fantastical stopped syncing in October 2026, the cause is almost always the same. Microsoft began blocking Exchange Web Services (EWS) in Exchange Online tenants on October 1, 2026, and Fantastical accounts that were added years ago as Exchange or EWS based Microsoft 365 accounts lose their connection when that happens. The fix is to move the account to Microsoft Graph, which Fantastical has preferred for new Microsoft 365 accounts since version 4.1.8 in February 2026.

This guide explains what the switch means, how to tell which kind of account is in use, what changes after moving to Graph, and what to ask an IT admin for. Dates and limits come from Microsoft's Exchange team blog and from Flexibits' own help pages and release notes, all checked on October 18, 2026.

What Microsoft Graph replaces, and why it matters now

Fantastical can talk to a Microsoft 365 calendar in two ways. The older one is EWS, a protocol Microsoft built nearly twenty years ago. The newer one is Microsoft Graph, a single API that covers mail, calendars, contacts, and tasks across Microsoft 365.

Microsoft announced the end of EWS in Exchange Online back in September 2023, in Retirement of Exchange Web Services in Exchange Online. A later post, Exchange Online EWS, Your Time is Almost Up, dated February 5, 2026, set out the schedule that is now in effect:

Date	What happens in Exchange Online
Before October 1, 2026	EWS allowed by default in every tenant
From October 1, 2026	Tenants that took no action have EWS switched off by default
Any time before April 2027	An admin can turn EWS back on, with a service interruption first
April 1, 2027	EWS fully and permanently disabled, with no exceptions

Two details on that page matter to Fantastical users. First, the change applies only to Microsoft 365 and Exchange Online. EWS on an on-premises Exchange Server is not affected. Second, a tenant admin who prepared an allow list before the end of September 2026 could keep EWS running for named apps until the final shutdown.

So whether a given Fantastical setup broke on October 1 depends on what the company's admin did in September. Either way, every Microsoft 365 account still on EWS stops working by April 1, 2027. Moving to Graph is not optional, only the timing is.

How to tell which sync method an account uses

Flexibits changed the default in stages, and the Fantastical release notes show the order:

• Version 4.1.5, December 3, 2025: added an option to migrate Exchange based Microsoft 365 accounts to Microsoft Graph.
• Version 4.1.8, February 10, 2026: Microsoft Graph became the preferred method for newly added Microsoft 365 accounts.
• Versions 4.2 to 4.2.3, September and October 2026: a run of Graph fixes, including invitee options on Graph events, improved syncing of Graph accounts in 4.2.2 on October 1, and a GCC High fix in 4.2.3 on October 13.

That gives a simple rule of thumb. A Microsoft 365 account added on version 4.1.8 or later, using the Microsoft 365 account type, is on Graph. An account added before December 2025, or one added with the plain Exchange account type and an email and password, may still be on EWS.

The account type matters as much as the date. The Getting Started guide for Mac says that if an organization uses Microsoft 365, the account should be added as a Microsoft 365 account rather than an Exchange account. The Microsoft 365 type signs in through Microsoft, so single sign-on and multi-factor authentication work, and the same page states that adding the account now uses Microsoft Graph syncing.

To check, open Fantastical, then Settings, then Accounts, and look at how the work account is listed. An account labeled Exchange that points at a Microsoft 365 mailbox is the one to move.

Moving a Microsoft 365 account to Graph

There are two routes, and both start in Settings, Accounts.

Route 1: use the migration option. On Fantastical 4.1.5 or later, Flexibits added an in-app option to migrate an Exchange based Microsoft 365 account to Graph. Update Fantastical first, since the Graph fixes in versions 4.2.2 and 4.2.3 matter for anyone switching now.

Route 2: remove and add the account again. If the option is not visible, the fallback is to remove the Exchange account and add it back:

1. In Settings, Accounts, select the old Exchange account and remove it.
2. Click the plus button at the bottom of the sidebar.
3. Choose the Microsoft 365 account type and click Continue.
4. Sign in through the Microsoft page, including any single sign-on or multi-factor step.
5. Wait for the first sync to finish before editing events.

The events themselves are stored in Exchange Online, not in Fantastical, so they return once the re-added account finishes syncing. Calendar sets that referred to calendars on the old account are worth checking afterward, since the calendars are attached to a new account entry.

The Getting Started guide also warns about one trap during this step. A single Flexibits Account covers every device, and signing in with a different method than the original one, for example email and password instead of Sign in with Apple, creates a second Flexibits Account and causes sync and subscription problems.

What changes after the switch

Graph is not a one to one replacement for EWS, and the gaps show up in shared calendars. Flexibits documents them in Why can I not see my Microsoft delegated calendars in Fantastical.

A delegated calendar can come through limited when the owner shared it with "Everyone in the organization" rather than directly with a person. In that case the Flexibits article lists four limits:

• View only: events cannot be added, edited, deleted, or answered.
• Main calendar only: none of the owner's other calendars appear.
• Few details: only titles and locations, or only Busy, Tentative, or Out of Office, depending on how it was shared. No notes, attendees, or meeting links.
• Short date range: about two weeks back and six weeks ahead.

The fix is on the owner's side. They need to share the calendar using the "Directly with" option in Outlook, with at least "Can view all details" access. Fantastical then switches the calendar to the new settings on its own.

Two calendar types do not come through Graph at all, according to the same article: calendars created through Microsoft Teams, and some group calendars. Anyone who relied on a Teams channel calendar inside Fantastical should expect it to disappear after the move.

The Settings help page adds that shared calendars added to the account in the Microsoft web interface should show up in Fantastical. If a colleague's calendar is missing, adding it in Outlook on the web first is often enough.

What to send the IT admin

Many organizations block third-party apps from Microsoft 365 until an admin approves them. If the Microsoft sign-in page returns an approval error, the Getting Started guide provides an admin consent link that authorizes Fantastical's client ID for the whole organization. An admin opens that link while signed in and approves it once.

Security teams usually want more than a link. Flexibits keeps two pages for them:

• Microsoft 365 scopes used by Fantastical and Cardhop lists each permission. It states the app uses delegated access, meaning it has the same permissions as the signed-in user and nothing more. Scopes include Calendars.ReadWrite and Calendars.ReadWrite.Shared for events, Tasks.ReadWrite for tasks, People.Read for invitee lookup, and Place.Read.All for rooms.
• Getting Fantastical and Cardhop approved by your IT or security team points to the Flexibits Trust Center, a SOC 2 Type II report, an annual penetration test summary, and Microsoft 365 Certification. It also includes a short template message to send to IT.

One more item to raise with the admin: the EWS state of the tenant. If the admin re-enabled EWS temporarily after October 1, Fantastical may appear to work on the old account until April 1, 2027 and then stop. Asking whether EWS is on, and moving to Graph regardless, avoids a second outage in the spring.

If sync still fails after the move

Three checks cover most remaining cases. First, confirm the app is on version 4.2.3 or later, since that release fixed syncing for Microsoft Graph GCC High, a Microsoft cloud for US government customers. Second, if Fantastical asks to sign in to Microsoft 365 again, that is expected: Flexibits explains in a short support note that the app requests additional access to create Microsoft Teams meetings, and reauthorizing grants it. Third, an admin can look at the EWS usage reports in the Microsoft 365 admin center, which the Exchange team recommends for finding apps still calling EWS. If Fantastical still shows up there after the move, check the iPhone, iPad, and any other Mac for an account that was never moved.

Deciding whether Fantastical is still the right fit

The Graph switch is a natural moment to check whether the setup still matches the need. Four questions settle most of it.

Which devices? On the US Mac App Store, Fantastical requires macOS 12.4 or later, and the iPhone version requires iOS 17.6 or later. The same listing shows Flexibits Premium as in-app purchases of $6.99 and $56.99, and Premium for Families at $10.49 and $89.99, as of October 18, 2026. Flexibits also states that Premium starts with a 14-day free trial, and that the trial must be cancelled at least 24 hours before it ends to avoid a charge.

Which accounts? Fantastical supports Google, Microsoft 365, Exchange, iCloud, CalDAV, and Todoist. A Microsoft 365 user who depends heavily on delegated calendars should test the Graph limits above before committing for a year.

Who is scheduled with? The Flexibits pricing page lists Fantastical Scheduling, which covers Openings and Proposals, under the Individual plan, and Openings with multiple hosts under the Team plan. Calendar Mirroring copies events from one calendar to another, and its help page notes the destination must support custom properties, which is true for CalDAV, Exchange, and Graph.

Subscription or not? Flexibits Premium is a subscription. Some Mac calendar apps sell outright. The price structures across the category are laid out in Compared with other calendars.

For a Mac user whose work calendar is Google rather than Microsoft, none of the Graph issues apply, and the choice becomes mainly about features and pricing model. The Features page of one native Mac calendar shows what a Google only desktop calendar covers.

What to change first

Open Settings, Accounts, and find any Microsoft 365 mailbox listed as Exchange. Update Fantastical, then migrate that account or re-add it as Microsoft 365, and ask colleagues to share key calendars "Directly with" the user. If the Mac calendar in use connects only to Google accounts, Caltimate is one option sold either as a subscription or as a one-time license.