I’ve had this conversation hundreds of times. A founder or MD sits across from me and says: “We know we need technology leadership, but we can’t justify a £150k salary.” And then they ask the question that brought you to this article: should we hire a full-time CTO, or can we get away with a fractional one?
The honest answer is that both models work brilliantly — when matched to the right situation. I’ve seen fractional CTOs transform businesses that couldn’t afford a full-time hire. And I’ve seen companies waste a year with a part-time arrangement when they genuinely needed someone in the chair every day. The difference comes down to four factors: your technology complexity, team size, growth trajectory, and budget reality.
The real cost comparison
Let’s start with the numbers, because they’re stark. A full-time CTO in the UK typically commands a base salary of £120,000 to £180,000. Add employer’s National Insurance (13.8%), pension contributions (5% minimum), private health insurance, and the equity or bonus package most senior hires expect, and you’re looking at a total cost of £160,000 to £240,000 per year. That’s before recruitment fees — typically 20 to 25% of salary — and the 3 to 6 months it takes to find the right person.
A fractional CTO engagement typically runs £1,500 to £6,000 per month, depending on the number of days and complexity. For most SMEs, 2 to 4 days per month is sufficient. That’s £18,000 to £72,000 per year — roughly 15 to 40% of the full-time cost. No recruitment fees, no notice period, no equity dilution. You can start next week, not next quarter.
I wrote a detailed breakdown of fractional CTO pricing in the UK if you want the granular numbers. But cost alone shouldn’t drive this decision.
When a fractional CTO is the right choice
The fractional model works best for companies in a specific band: large enough to need strategic technology guidance, but not so large or complex that technology decisions happen every hour. In my experience, that’s most UK businesses with 10 to 150 employees and annual technology spending between £50,000 and £500,000.
Here are the signals that point to fractional:
Technology supports your business but isn’t your product.If you’re a professional services firm, a logistics company, a retailer, or a manufacturer, technology is a critical enabler — but it’s not what you sell. You need someone to make smart decisions about your tech stack, security, and vendors. You don’t need them in the office five days a week to do it.
Your development team is small or outsourced.If you have 1 to 8 developers (in-house or agency), a fractional CTO provides the architectural oversight and code quality standards they need without the overhead of a full-time executive. I typically review pull requests, set technical direction, and run fortnightly architecture sessions — enough to keep a small team on track.
You’re not sure what you need yet.Many businesses come to me because they know something is wrong with their technology but can’t articulate what. A technology health check followed by a few months of fractional engagement often clarifies the picture before you commit to a permanent hire.
You need breadth, not depth.A fractional CTO who works across multiple businesses brings pattern recognition that a single-company CTO can’t match. I’ve seen what works and what fails across dozens of industries. That breadth is worth more than daily presence for most SMEs.
When you genuinely need a full-time CTO
There are situations where fractional isn’t enough. I’m honest about this with every prospective client, because recommending the wrong model wastes everyone’s time.
Technology is your core product.If you’re building a SaaS platform, a fintech product, or any business where the technology itself is what customers pay for, you need a CTO who lives and breathes the product every day. Technical decisions in product companies happen constantly — architecture trade-offs, build-vs-buy choices, performance optimisation, security incidents. A few days a month isn’t sufficient for that velocity.
You have more than 20 developers.Once your engineering team crosses roughly 20 people, the management overhead alone requires dedicated leadership. You’re dealing with team structures, hiring pipelines, promotion frameworks, on-call rotations, and cross-team coordination. That’s a full-time job.
You’re preparing for a significant funding round or exit.Investors and acquirers want to see a permanent technology leader on the executive team. While a fractional CTO can help you prepare for due diligence — and I often do exactly that — the long-term expectation is a full-time hire. If you’re raising Series A or beyond, start planning the transition.
Your tech spend exceeds £500,000 per year. At that budget level, even a 5% improvement in efficiency from dedicated leadership more than pays for the salary. The ROI arithmetic shifts decisively toward full-time.
The hybrid path: start fractional, grow into full-time
What I see work best for many growing businesses is a phased approach. Start with a fractional CTO to establish your technology strategy, clean up vendor relationships, implement security basics, and build processes. Then, when the business reaches the complexity threshold, transition to a full-time hire.
The fractional CTO can even help you recruit their replacement. I’ve done this multiple times — writing the job specification, screening candidates, conducting technical interviews, and then spending 2 to 3 months onboarding the new CTO before stepping back. It’s a much lower-risk path than hiring cold.
This hybrid approach also protects you from a common failure mode: hiring a full-time CTO before you know what you actually need. I’ve seen companies hire a £150,000 CTO only to discover that their real problem was a £3,000 per month vendor management issue. The fractional phase gives you clarity before you commit.
A decision framework you can use today
If you’re still unsure, answer these five questions:
1. Is technology your product or your tool? Product = lean full-time. Tool = fractional.
2. How many developers do you have? Under 15 = fractional. Over 20 = full-time. 15 to 20 = either, depending on growth plans.
3. How often do critical tech decisions need to be made? Weekly or less = fractional. Daily = full-time.
4. What’s your annual technology budget?Under £500,000 = fractional almost certainly makes more sense. Over £500,000 = evaluate full-time.
5. Are you fundraising in the next 12 months?If yes, consider starting fractional now and hiring full-time as part of the raise. Investors like seeing that you’ve already established technical rigour.
If you answered “fractional” to three or more of those questions, that’s almost certainly where you should start. If you’re still on the fence, the AI Readiness Quiz will give you a more detailed picture of where your technology leadership gaps are.
What a fractional CTO actually does (in practice)
There’s sometimes confusion about what the engagement looks like day-to-day. In a typical month, I might review your cloud infrastructure costs and find £800 in savings, conduct a security audit that catches an unpatched vulnerability, negotiate a software renewal that saves 30%, and spend two hours mentoring your lead developer on architecture decisions.
I attend your leadership meetings, contribute to board packs, and I’m on call for urgent decisions. The difference from a full-time CTO is that I’m not in the office every day — but I’m always available when it matters. If you’re seeing the warning signs that technology leadership is missing, that’s worth a conversation.
The bottom line
For the vast majority of UK SMEs, a fractional CTO delivers better value than a full-time hire. You get senior expertise without the overhead, breadth without the cost, and flexibility without the commitment. The companies that genuinely need a full-time CTO usually already know it — because their technology complexity makes the decision obvious.
If you’re reading this article, you’re probably in the fractional camp. And that’s not a compromise — it’s the smart play. Book a free 15-minute consultation and let’s figure out what your business actually needs.