For most UK businesses with between 10 and 100 staff, a well-run move from Google Workspace to Microsoft 365 takes two to six weeks from kick-off to finish. The part your team actually notices, the switchover itself, usually happens over one evening or weekend.
That range is wide because the calendar time is driven less by the number of people and more by how much data you have, how it is organised, and what else is connected to your Google accounts. Here is how the time breaks down, and what you can do to keep it short.
The short answer
| Business | Typical timeline | Switchover |
|---|---|---|
| Up to 20 users, mostly email | 2 to 3 weeks | One evening |
| 20 to 100 users, email plus Google Drive | 3 to 6 weeks | One weekend |
| Large Drive libraries, shared drives, many connected apps | 6 to 10 weeks | One weekend, sometimes in stages |
The five stages of a migration
1. Discovery and planning (about a week)
Before anything moves, we work out what you actually have. That means mailbox sizes, how much is in My Drive and shared drives, shared calendars and resource bookings, and which other apps people sign in to with their Google account. We also check who controls your domain and DNS, because the switchover depends on changing your email records. A few days before the switchover, we shorten how long those records are cached (the TTL), so the change takes effect in minutes rather than hours.
The output is a plan: what moves where, the order it moves in, and the date of the switchover.
2. Setting up Microsoft 365 (a few days)
Your Microsoft 365 tenant is set up and secured before anyone uses it: your domain is verified, users and licences are created, multi-factor authentication and sensible security settings are switched on, and the SharePoint and Teams structure is in place for your shared files.
Doing this properly at the start is much easier than tidying it up later.
3. Copying data in the background (days to weeks)
This is where most of the calendar time goes. Email, calendars, contacts and files are copied from Google to Microsoft 365 while your team carries on working in Google as normal. Nobody is disrupted, and there is no rush: the bulk of the data is in place well before the switchover.
How long this takes depends almost entirely on volume. A business with modest mailboxes and little in Drive can be fully copied in a few days. Hundreds of gigabytes of Drive files take longer, because both Google and Microsoft limit how fast data can be moved out of and into their services.
4. The switchover (an evening or a weekend)
When everything is copied, we pick a quiet time, usually a Friday evening, and:
- change your domain’s email records so new mail arrives in Microsoft 365
- run a final sync to catch anything that arrived or changed since the background copy
- check mailboxes and files are complete
On Monday morning, your team signs in to Outlook, Teams and OneDrive and everything is where they expect it. The one thing they do need to do is add their new account to Outlook and to the email app on their phone; we send simple instructions in advance and help anyone who gets stuck.
5. Hypercare (about two weeks)
The first fortnight is when people find the shared calendar that did not come across quite right, or need help reconnecting their phone. We stay on hand to fix those quickly and help people settle in.
What makes a migration take longer
- Large or messy Google Drive libraries. Lots of data takes longer to copy, and shared drives with complicated permissions need mapping to a sensible SharePoint and Teams structure rather than being copied as they are.
- Apps that use “Sign in with Google”. CRMs, accounting tools and other software where people sign in with their Google account need moving to Microsoft sign-in, or at least checking, before Google accounts are switched off.
- Not knowing who controls your domain. If nobody has the login for your domain registrar or DNS provider, finding it can hold everything up. It is worth checking early.
- Lots of shared mailboxes, groups and aliases. Google groups and aliases behave differently in Microsoft 365, so each one needs a decision.
- Things that do not move automatically. Google Forms, Google Sites, Apps Script automations and Google Chat history have no direct equivalent and are not copied by migration tools. Docs and Sheets are converted to Word and Excel, and complex formulas, add-ons or comment threads can come out differently. Each needs a decision: rebuild, export or retire.
- Devices. If laptops and phones are also moving to Microsoft management with Intune, that is usually done as a second step after the email and file move.
How to keep it quick and calm
- Find your domain login now. You will need access to wherever your DNS is managed.
- Tidy up Drive before you move it. Deleting old duplicates and leavers’ files means less to copy and a cleaner result.
- List the apps people sign in to with Google. Even a rough list saves time later.
- Keep your Google licences for a month after the switchover. That gives you a safety net while everyone settles in. Cancel them once you are sure nothing is missing. Check your Google plan first: on an Annual or Fixed-Term plan you usually cannot cancel mid-term, so time the move around your renewal date if you can.
- Tell your team early. A short message about what will change, when, and who to ask goes a long way.
Thinking about making the move?
We handle Google Workspace to Microsoft 365 migrations at a fixed price, with the switchover done out of hours and two weeks of support afterwards. See how our Microsoft 365 migration service works, or get in touch for an honest view of how long your move would take.