How to choose a marketing agency in 2026.

First decision: large or small agency?

London alone has everything from solo studios (us) to 200-person agencies. Which is right depends entirely on your size and needs.

Small agency (1–10 people): right for small businesses with 1–30 employees. Lower overhead, direct contact, faster response, lower price. Typical pricing: £500–2,500/month.

Mid-size agency (10–50 people): right for businesses with 30–200 employees. More process, more specialists, broader expertise. Typical pricing: £2,500–8,000/month.

Large agency (50+ people): right for large businesses (200+ employees, often listed). Full strategy teams, multidisciplinary projects. Typical pricing: £8,000–40,000+/month retainer.

10 questions to ask before signing

1. Who's actually working on my project? (Get names. If "we'll assign later" — move on.)
2. Do I get direct contact, or does everything go via an account manager?
3. What's the minimum contract? (If 6 or 12 months without exit, be careful.)
4. Fixed price or hourly? (Fixed is almost always better for you.)
5. Do I own the accounts after we end? (Facebook BM, Google Ads, Pixel, creatives.)
6. How often do you report, and what metrics? (If "monthly with CTR and impressions" — move on. You want sales and leads.)
7. Can you show real case studies with numbers? (Concrete businesses, concrete numbers. Not vanity metrics.)
8. What's the guaranteed delivery time? (Concrete number of days, not "as fast as we can".)
9. What happens if you miss the deadline? (A confident agency dares to say "we credit 10%".)
10. Can I call an existing client and ask about you? (If no — move on.)

The 5 most common traps

Trap 1: "Strategy phase" that costs £3,000 and delivers little

Many agencies start with a mandatory "discovery" or "strategy" phase of 4–8 weeks that costs £3,000–8,000. You get a beautiful Keynote document, and then the actual work begins (with a new invoice).

Better: demand strategy is included or max 1–2 hours. If they can't understand your business in 60 minutes, they have a method problem.

Trap 2: Accounts owned by the agency

The most damaging thing you can do is let an agency create your Facebook Business Manager, Google Ads account, Pixel and creative ads in their own name. If you stop using them, you've lost everything — start from zero with new algorithm history.

Requirement: all accounts in your name, agency gets partner access via their system. Never the reverse.

Trap 3: Retainer without output spec

"We charge £2,500/month and deliver marketing." What is "marketing"? How many ads? How many posts? How many reports?

Requirement: specify concrete monthly deliverables.

Trap 4: Vanity metrics in reports

Many agencies report "impressions", "reach" and "engagement" — because these numbers always go up regardless of whether anything actually happens.

Requirement: the report should contain 3 things — cost per lead/sale, total leads/sales, and ROAS.

Trap 5: "We do everything" — no one is good at everything

If an agency says they're equally good at SEO, Google Ads, Meta ads, content, branding, video, podcast and TikTok — they're probably not great at any of them.

Better: an agency that's honest about what they're good at AND what they don't do.

"The best agency is often the one that says no to things they're not best at."

Conclusion

The best agency for you isn't the biggest, most expensive, or the one with the most awards. It's the one that matches your size, gives honest answers, and that you can sleep well paying. Ask the 10 questions above. Avoid the 5 traps. Demand fixed price and ownership. You'll be ahead of 80% of small businesses choosing an agency each month.