Co-managed IT support is a model where your internal IT team keeps control of day-to-day priorities while an external provider adds specific capacity, tools or expertise — a shared arrangement, not a full handover. In London it typically costs £15–£45 per user per month, or a fixed retainer, depending on what you delegate.
What co-managed IT actually means (and what it doesn't)
Co-managed IT is a partnership. Your in-house staff — whether that's one overstretched IT manager or a small team — retain ownership of strategy, user relationships and the systems they know best. The external provider plugs the gaps: 24/7 cover, specialist security, project muscle or enterprise-grade monitoring tools that would be expensive to buy alone.
It is not fully outsourced IT, where a provider takes over everything and your internal role disappears. It is also not simply buying licences or a help desk number. The defining feature is a clear, agreed split of responsibilities, backed by shared tooling and regular communication.
Think of a practical example. Your IT manager handles starters, leavers and the line-of-business app nobody else understands. The provider runs patching, endpoint protection and out-of-hours tickets so your manager isn't answering a 6:12pm call about a printer while on holiday. That is co-managed IT support working as intended.
When co-managed beats fully outsourced or in-house
Co-managed suits businesses that already have internal IT but can't cover everything well. Common triggers are growth, a security gap, holiday and sickness cover, or a one-off project that would swamp the existing team.
Fully in-house works when you have enough headcount to cover 24/7 rotas, security specialisms and project delivery — which, for most London SMEs, means a team larger than they can justify. Fully outsourced works when you have no internal IT at all, or when IT is not close enough to the business to warrant keeping it in-house.
Co-managed sits between the two. You keep institutional knowledge and quick internal decisions, while gaining the depth of a larger provider. It's particularly useful where compliance matters — bringing in managed detection and response or a managed SOC is far cheaper than hiring a security analyst your business can't keep busy full-time.
- Your IT manager is a single point of failure for leave and sickness
- You need 24/7 cover but can't justify a night shift
- A migration or office move needs hands you don't have
- Security has outgrown your team's time or tooling
- You want senior IT strategy (vCIO) without a full-time hire
What co-managed IT support costs in London: pricing models explained
There is no single price, but London co-managed arrangements usually follow one of three models. Per-user pricing is the most common and predictable: expect roughly £15–£45 per user per month depending on what's included, with security-heavy packages at the upper end. This scales cleanly as you hire.
Per-device or per-server pricing suits infrastructure-led needs — say, monitoring and patching servers and network kit while your team handles users. A fixed monthly retainer works where you want a defined block of specialist time, for example a set number of engineer days plus escalation cover.
Compare this to the cost of hiring. A mid-level IT support engineer in London carries a salary well into five figures before pension, recruitment, holiday cover, training and tooling. One hire gives you one skillset and no out-of-hours cover. A co-managed layer spreads a team of specialists across a monthly fee, which is why it often reads well against internal IT support cost on a spreadsheet. Always confirm what sits outside the fee — projects, hardware and third-party licences are usually quoted separately.
How responsibilities split between your team and the MSP
The split is the whole point, so it must be written down. A good provider documents it as a RACI (Responsible, Accountable, Consulted, Informed) matrix during onboarding, line by line, so nothing falls between two stools.
A typical arrangement has your internal team own user support, business-app knowledge and day-to-day prioritisation. The provider owns 24/7 monitoring, patching, backup verification, and security operations such as endpoint security (EDR) and identity protection. Project delivery and escalations are shared, with clear handover points.
Shared tooling makes this work. Both sides see the same ticketing, monitoring and documentation, so a job started by your manager can be finished by the provider's engineer without re-explaining it. Without that shared view, co-managed quickly becomes two teams emailing each other — which is slower, not faster.
How do I know if my business is ready for co-managed IT?
You're likely ready if you have at least one internal IT person whose time is being eaten by routine work, or who can't cover the hours and specialisms the business now needs. The readiness question is less about size and more about pressure points.
Look at where things break. If tickets pile up during your IT manager's annual leave, if patching slips, if nobody has time to review security alerts, or if a planned project keeps being pushed back — those are gaps a co-managed layer fills directly. If, instead, you have no internal IT at all, fully managed IT support is usually the better starting point.
Being ready also means being willing to share access and documentation. Co-managed only works when the provider can see your environment and your team is comfortable collaborating rather than guarding. If knowledge currently lives in one person's head, onboarding a partner is also a sensible way to de-risk that.
Questions to ask a co-managed IT provider before you sign
Treat the sales conversation as a test of how the relationship will actually run. The answers tell you whether you're buying a partner or a passive licence.
Ask who does what, in writing, and how disputes over ownership get resolved. Ask about response times and whether they're guaranteed in a service level agreement. Ask which tools you'll share, whether you keep access if you leave, and who owns the documentation. Clarity now prevents friction later.
Finally, probe their security and connectivity depth, because that's where most London SMEs need the most help. A provider that can also support network security, Microsoft 365 and your leased line or connectivity under one accountable team removes the finger-pointing that happens when IT, security and telecoms sit with different suppliers.
- Can you give me a written responsibility (RACI) matrix?
- What are your response and resolution SLAs, out of hours included?
- Which tools do we share, and do we keep access if we leave?
- Who owns the documentation of our environment?
- How do you handle security alerts and escalations?
- What's inside the monthly fee, and what's billed separately?