Guide · By Tristan Gillen, fractional CMO · Updated
What is a fractional CMO? A guide for UK and European startups
A fractional CMO is a senior marketing and growth leader who works with a company part-time, usually a few days a month, instead of as a full-time employee. They own the marketing strategy, set growth targets, build and lead the team and process, and are accountable for results, at a fraction of the cost of a full-time Chief Marketing Officer.
I've worked with over 100 startups as a founder, growth agency founder, advisor and fractional CMO. This guide is what I tell founders who ask whether they need one, and how to get it right if they do.
What is a fractional CMO?
"Fractional" means you get a fraction of a senior executive's time. The role is the same as a full-time CMO, owning how the company finds, wins and keeps customers, but the commitment is part-time and flexible. Typical engagements are 2 to 6 days a month for startups and scale-ups, over 6 to 18 months.
The model has grown fast in the UK and Europe because most startups need senior growth leadership long before they can justify, or find, a full-time CMO.
What a fractional CMO actually does
The job changes with your stage, but it usually covers six things:
- Go-to-market strategy. Who you sell to, what you say and which channels you use to reach them.
- Growth targets and metrics. A North Star metric, realistic targets and a monthly rhythm that holds the team to them.
- Channel validation. Testing channels with clear hypotheses, then scaling the winners and cutting the rest.
- Team building. Deciding what to hire, outsource or automate, then hiring and coaching the team.
- Systems. Tracking, CRM, attribution and automation so decisions are based on data.
- Leadership. Representing marketing to the founders and board, and aligning it with sales and product.
A good fractional CMO is measured on outcomes, not activity. At Startups.com, for example, the value was as much in ruling out three channels as in validating three that worked.
Fractional CMO vs full-time CMO, interim CMO, consultant and agency
| Commitment | Owns results? | Typical cost | Best for | |
|---|---|---|---|---|
| Fractional CMO | Part-time, ongoing | Yes | £3k to £12k / month | Startups and scale-ups needing senior leadership, not yet a full-time role |
| Full-time CMO | Full-time, permanent | Yes | £100k to £195k+ / year fully loaded | Larger teams that need daily leadership |
| Interim CMO | Full-time, fixed term | Yes, for the term | Day rate, full-time | Covering a gap or a turnaround |
| Marketing consultant | Project-based | Usually not | Project fee | A specific question or audit |
| Marketing agency | Retainer, by channel | For their channel | Retainer plus media | Executing a channel you've already chosen |
The key difference is ownership. Agencies and consultants are valuable, but someone still has to decide the strategy, choose and manage them, and be accountable for the overall number. That's the CMO's job, fractional or not.
When to hire a fractional CMO
The clearest signs you're ready:
- You have early traction, but growth is founder-led and not repeatable.
- You're spending on marketing but can't say which channels drive revenue.
- A generalist marketing hire hasn't moved the numbers.
- You've raised a round and need a credible growth plan for the board.
- You're entering a new market, like the UK, Europe or the US, or adding a B2B line to a B2C business.
- You need to hire a marketing team and don't know what good looks like.
When it's too early: before you have any evidence of product-market fit, a fractional CMO's process has little to work with. Founder-led customer conversations and cheap experiments come first; my free weekly mentoring sessions are a better fit at that stage.
What the first 90 days should look like
- Weeks 1 to 3: diagnose. Customers, numbers, tracking, current channels and team. Fix measurement first.
- Weeks 3 to 6: strategy. ICP, positioning, North Star metric, targets and a ranked list of channels to test.
- Weeks 6 to 12: experiments and team. Run the first structured channel experiments, set the weekly and monthly rhythm, and decide what to hire, outsource or automate.
By day 90 you should know which channels are worth scaling, and have a team and process to scale them.
How to choose a fractional CMO
- Relevant experience. Have they done this at your stage and in your model (B2B, B2C, SaaS, marketplace)?
- Specific results. Ask for case studies with real numbers, not just logos.
- A clear process. They should be able to describe their first 90 days without hesitating.
- Strategy and execution. At startup stage you need someone who can do the work, not just direct it.
- Fit with your team. They'll be leading your people, so speak to a former client.
Red flags
- Promising results before they've seen your data.
- A fixed "playbook" that's the same for every company.
- No interest in tracking, attribution or the numbers.
- Only strategy decks, no hands-on work, at seed stage.
- Pushing you to buy their agency's services before agreeing the strategy.
How much does a fractional CMO cost?
In the UK, most fractional CMOs charge £3,000 to £12,000 a month, based on 2 to 6 days a month. See the full breakdown in my fractional CMO cost guide.
Thinking about a fractional CMO?
I work with startups and scale-ups across the UK and Europe. Book a free 30-minute call and I'll tell you honestly whether you need one yet.