How to stop double-booking across clients or jobs

You get double-booked across clients or jobs because each one gives you a calendar inside theirsystem, and none of those calendars can see the others. A client books you at 2pm on Tuesday in their Google Workspace; your other client's Outlook still shows Tuesday 2pm as free, so they book it too. The fix is to make every calendar know when you are busy without any of them learning why. There are four ways to do that: keep one calendar as the source of truth and block the rest by hand, forward invites to a personal calendar, mirror busy-only blocks between all of them automatically, or stop sending booking links that only read one calendar.

Why this happens to contractors specifically

An employee with one calendar rarely gets double-booked; the calendar does the checking. A consultant with three clients has three calendars in three organisations, and typically a personal one on top. Every scheduling decision anyone makes about you is made against one of them, with no knowledge of the other three.

Booking pages make it worse, not better. Most read a single connected calendar for conflicts, so the slots they offer are “free” only in that one calendar's view of the world. Sending a link like that to a new client is how Tuesday 2pm gets booked twice.

Fix 1: One source of truth, blocked by hand

Pick one calendar — usually personal — as the truth, and whenever something lands on a client calendar, add a matching “Busy” block to it. Then send availability only from that one.

This works well with two calendars and falls apart at three. The failure is silent: a client reschedules, you forget to move the copy, and now the truth calendar is wrong. It also does nothing for the client calendars themselves, which still show you as free to everyone inside those organisations.

Fix 2: Forward invites to a personal calendar

Set each client account to forward or auto-accept invites into your personal calendar, so at least one place sees everything. Cheap, and better than nothing.

Two problems. It is one-directional: your personal calendar learns about the clients, but no client calendar learns about the others, so people at each client still book over each other. And it copies full event details — titles, attendees, agendas — from every client into one personal account, which is usually the opposite of what you agreed to in a contract with a confidentiality clause.

Fix 3: Mirror busy-only blocks between all of them

The version that actually solves it: every time an event lands on any of your calendars, a plain “Busy” block appears at the same time on all the others. Client A's calendar shows you are unavailable Tuesday 2pm; it does not show that Client B booked you, or what for. Reschedule the original and the copies follow.

Doing this by hand is Fix 1 with more calendars. Doing it automatically is what calendar-sync tools are for — the detail to check is that the tool can copy a busy block without the title, so nothing confidential crosses between clients. Our guide to syncing Google and Outlook calendars walks through the options, including the free ones and what they leak.

Fix 4: Stop sending links that read one calendar

Even with perfect mirroring, the way you offer time matters. If the link you send reads one calendar, it offers slots that one calendar thinks are free. Send availability that is merged across every calendar you have, and the offered times are true by construction.

BusyBoard is the automated way for both halves: it mirrors busy-only blocks between your calendars so each one knows when you are unavailable, and it gives you one link that shows your real free time across all of them — with any booking landing for your approval before it touches a calendar. The people you send it to see when you are free, never which client has you when. The availability link is free; mirroring between calendars is part of Pro, with a 14-day trial and no card required.

The rule that prevents all of it

Never let anyone — a person or a tool — decide you are free using fewer calendars than you actually have. Every double-booking traces back to a decision made against an incomplete picture. Make the picture complete first; the rest is detail.