Most London firms decide to switch IT provider months before they actually do it. The delay is almost never about the provider — it is the fear that changing IT support means a week of chaos, lost email, and nobody able to log in on Monday.

Done properly, a switch costs you no downtime at all. The users notice a new number to call and very little else.

Three things cause the disruption people fear, and all three are avoidable if you handle them before you give notice:

The notice period. Most managed IT contracts auto-renew and carry 30 to 90 days’ notice. Find out which yours is before you start conversations, or you will pay two providers at once.
Who owns the tenant. If your Microsoft 365 or Google Workspace tenant sits under your provider’s partner account rather than your own, they control your identity platform. This is the single most common thing that complicates an otherwise straightforward exit, so confirm early who the tenant belongs to.
Where the documentation lives. Passwords, licence records, network diagrams and warranty details are often held in the incumbent’s own systems. If you have never been given copies, ask for them now rather than in the middle of a handover.

This guide is the IT provider transition plan we use for our own onboardings: what to document, what to ask, what to get in writing, and the order to do it in.

Spot the signs it is time to switch IT provider

Before you commit to anything, check the problems are real and not just unclear expectations on both sides. These are the signs the relationship has genuinely broken down:

Response times have slipped and SLAs get missed with no acknowledgement and no plan to fix it.
The same issues keep coming back because nobody looks for the root cause.
Security is weak — no MFA enforcement, no EDR, patching behind, no security reviews.
They only ever react. You never hear from them unless you raise a ticket.
They cannot keep up with you. Your business has moved on and their capability has not.
You cannot see anything. No reporting, no documentation, no service reviews.
Everything sits with one engineer. When that person is away, nothing moves.

If three or more of those ring true, start planning your switch.

Step 1: Document what you already have

Before you speak to anyone new, write down what you have. That inventory becomes the backbone of your transition plan, and it lets new providers scope a proposal that is actually accurate.

Capture the following:

User count and locations (office, remote, hybrid split)
Devices (laptops, desktops, phones, printers, meeting room equipment)
Servers and infrastructure (on-premise, co-located, or cloud)
Software and licences (Microsoft 365 tenant, line-of-business applications, security tools)
Network infrastructure (firewalls, switches, access points, internet connections)
Domain registrations and DNS (who holds the registrar account?)
Backup systems (what is backed up, where, and how often?)
Key contracts and renewal dates (hardware warranties, software subscriptions, internet circuits)
Open issues and known problems (what is currently broken or suboptimal?)

If your current provider cannot supply this documentation, that is worth noting in itself: keeping it current is one of the clearest signs of a well-run service.

Step 2: Read your contract before you give notice

Check your existing MSP contract for four things:

Notice period. Most MSP contracts want 30 to 90 days. Some auto-renew and extend the term if you miss the notice window.
Termination provisions. Look for early termination fees, minimum commitments and penalty clauses.
Data and access obligations. Your contract should say that all your data, credentials and documentation come back to you on termination. If it does not, raise it in writing before you give notice.
IP and asset ownership. Confirm that scripts, configurations and customisations built for your environment belong to you, not to them.

Step 3: Choose your new provider on evidence, not a pitch

Run a structured evaluation. Do not decide on one recommendation or a good sales meeting. Test them on four fronts.

Whether they can actually run your stack

Can they support your specific technology stack?
Have they worked in your industry before?
Which security certifications do they hold?
What do they use for monitoring, management and security?

Pin down how they will support you

What are their SLA commitments for response, resolution and availability?
How do they handle out-of-hours and emergencies?
What does their onboarding actually involve?
How often will you get a service review?

Whether you will enjoy dealing with them

Do they communicate clearly, before you have to chase?
Will they explain things in plain language?
Do they push back when you are wrong, or just agree with everything?

The commercial terms, in plain numbers

Is the pricing transparent and predictable?
What sits inside the base price, and what gets billed on top?
What does the commitment look like, and are there exit penalties?

Then ask for references from businesses your size in your sector, and make the time to call them.

Step 4: Plan the transition before anyone touches anything

A well-planned transition takes two to four weeks. Your new provider should own the project management. You still need to be in the room for the decisions that matter.

Tick these off before the switch starts

New provider completes a technical audit of your environment
Transition plan with specific dates and responsibilities is agreed
Communication plan for your team is prepared
Fallback plan defined in case of unexpected issues
All credentials and admin access confirmed as obtainable

Taking back every credential and admin account

This is the part that goes wrong most often, so give it the most attention. Your new provider needs:

Microsoft 365 global admin credentials (or a new admin account created)
Domain registrar access
Firewall and network equipment admin credentials
Server admin credentials
Backup system access
Any vendor portal logins (hardware warranties, ISP accounts, etc.)

Your outgoing provider is obliged to hand these over. If they stall, escalate in writing and quote the contract clause. And if it really comes to that, Microsoft and the domain registrars both run ownership-recovery processes you can fall back on.

Overlap the two providers for a week or two

Give both providers access for a short overlap. Your new team learns the environment while the outgoing one is still around to answer handover questions. One to two weeks is usually enough.

Step 5: Make the switch, then cut the old access

On the day, and through the week around it:

Tell your team what is happening. Say what changes, when, and who to call for IT support during and after the move.
Update the help desk details everywhere. Everyone needs the new number, the new email and the new ticketing system.
Check monitoring and alerting fire. Confirm the new tools are live and alerting before you decommission the old ones.
Test backup and recovery. Your new provider should prove backups run and complete a test restore.
Change every shared credential. If the outgoing provider knew a password, change it.
Revoke the old provider’s access. Remove their admin accounts, VPN credentials and remote access tools.

Step 6: Review the first 30 days with your new provider

Book a review inside the first 30 days. Cover four things:

Anything that went wrong during the transition
Documentation gaps that still need filling
Quick wins and improvements they have spotted
An agreed roadmap for the next 90 days

Four mistakes that cause real downtime

Giving notice before you have chosen a replacement. That leaves a window with no support at all.
Leaving your credentials until later. If you do not hold admin access to your own systems, fix that first.
Rushing to save a few pounds. A botched switch costs far more than a couple of extra weeks of overlap.
Saying nothing to your team. Staff who do not know the process changed will keep ringing the old provider.

Switching providers without losing a working day

We have moved dozens of London businesses onto our managed IT support from another provider, and we run the same documented process every time. It covers a full technical audit, a written transition plan, a parallel running period and a 30-day review once you are live.

If you want to see what London-based IT looks like with us, start with our free IT assessment. We will go through your current setup, point out what we would fix first, and map out how the transition would work for your business.

Switch IT Provider in London Without Downtime (2026)