Internal IT vs Outsourced IT vs Co-Managed IT: Which Is Right for Your Business?

Internal IT, fully outsourced IT and co-managed IT each work well in different situations — the right choice usually comes down to your size, budget, in-house skills and how critical technology is to what you do, not which model is theoretically "best."

Business owners often ask us to make the case for one model over the others, but in our experience the honest answer is "it depends" — and it's worth actually working through the dependency rather than defaulting to whichever model a given provider happens to sell. This guide sets out how each model works, where each tends to fit, and how to think about a switch between them.

The three models explained

Internal (in-house) IT

You employ IT staff directly, whether that's a single generalist "IT person" or a small team. They work exclusively for your business and typically sit within it day to day.

Outsourced (fully managed) IT

An external provider handles some or all of your IT — helpdesk, security, infrastructure management, strategy — under a support contract. You have no internal IT staff, or only a very light internal role coordinating with the provider.

Co-managed IT

A hybrid: you have some internal IT capability (often one person, or a small team focused on specific priorities) and an external provider fills the gaps — handling overflow support, specialist areas like cyber security, out-of-hours cover, or additional expertise the internal team doesn't have.

Comparison

	Internal IT	Outsourced IT	Co-managed IT
Typical fit	Larger SMEs and enterprises with complex, bespoke systems	Small to mid-sized SMEs without the scale to justify a full team	Growing SMEs, or those with a specific internal need alongside broader support gaps
Availability	Limited to working hours unless you pay for on-call cover	Often includes extended hours or 24/7 monitoring as standard	Combines internal presence with external out-of-hours backup
Breadth of expertise	Limited to what your hired staff know	Access to a wider team with varied specialisms	Best of both — internal knowledge of your business plus external specialist depth
Cost predictability	Salary, recruitment, training and turnover costs, often underestimated	Predictable monthly fee, scales with usage	Mix of fixed salary cost and variable/fixed external fee
Resilience to staff absence or turnover	Vulnerable — one person leaving can leave real gaps	Provider resilience covers absence and turnover	Shared resilience, though internal knowledge gaps still matter
Strategic input	Depends entirely on the individual's experience and time	Varies by provider — ask specifically what strategic input is included	Can combine internal business knowledge with external strategic experience
Security specialism	Rare for a generalist in-house IT person to have deep security expertise	Often included or available as an add-on	External partner typically covers specialist security needs

Where each model tends to make sense

Internal IT tends to suit:

• Larger businesses (typically 100+ staff, though this varies by complexity) with enough volume of work to keep a team fully occupied
• Businesses with highly bespoke or proprietary systems where deep, exclusive knowledge of the business is essential
• Organisations that can afford genuine resilience — more than one person, so a single departure doesn't create a knowledge gap

Outsourced IT tends to suit:

• Most SMEs under roughly 50–75 staff, where the workload doesn't justify a full internal team
• Businesses without existing IT expertise who need a broad, ready-made skill set from day one
• Businesses that want predictable monthly costs rather than the variable cost and risk of employing staff directly

Co-managed IT tends to suit:

• Growing businesses that have justified one internal IT hire but need more depth, particularly in cyber security or infrastructure, than one person can realistically cover
• Businesses with an internal IT person who's stretched too thin, covering everything from helpdesk tickets to strategic projects
• Organisations that want to keep institutional knowledge in-house while outsourcing specialist or out-of-hours needs

A worked example

Consider a fictional 40-person professional services firm that has grown from 10 staff over five years, supported the whole way by one in-house "IT generalist." As the firm grew, that person became responsible for helpdesk tickets, cyber security, supplier management and strategic planning — all at once, with no cover when they're on leave. A co-managed model, where that person focuses on day-to-day priorities and internal knowledge while an external partner covers security monitoring, out-of-hours support and specialist advice, often resolves this kind of bottleneck without the firm needing to hire two or three more staff.

Common mistakes

• Assuming outsourcing means losing control — a good contract (see our guide on what should be in a managed IT support contract) should give you as much visibility and input as you want, not less
• Hiring one internal generalist and expecting them to match the breadth of a full external team, particularly on security
• Sticking with an outgrown internal setup purely out of loyalty to a long-serving employee, rather than assessing the business's actual risk exposure
• Assuming co-managed is automatically more expensive than picking one model — cost depends entirely on scope, not the label

How to decide

1. Map out your current IT workload honestly — helpdesk volume, project work, security requirements, strategic planning
2. Assess how resilient you are to a single point of failure, whether that's one employee or one contract
3. Work out your appetite for managing HR overhead (recruitment, training, cover) versus a support contract
4. If you already have internal IT, be honest about where the actual gaps are — often security and out-of-hours cover — before assuming you need a full outsourced replacement
5. Cost out the realistic options using our guide on how managed IT support is priced

Recommendations

In our experience, most SMEs under around 50 staff are best served by outsourced or co-managed models, simply because the breadth of expertise needed to run IT and security properly is hard to replicate with one or two internal hires. Businesses with more complex, bespoke technology estates and the scale to support a full team may find a larger internal function justified. Whichever direction you're leaning, it's worth reviewing what a good contract should look like before committing — see what should be included in a managed IT support contract.

Related questions

• How much should managed IT support cost in the UK?
• What should be included in a managed IT support contract?
• How to switch IT providers without disrupting your business

If you're weighing up these options for your business, take a look at our managed IT support page, or get in touch for an honest conversation about which model fits.