Most advice on how to choose a social media agency is written by agencies, and so is this, so we have made it the checklist we would want a client to use on us. The short answer is simple. Write a one page brief, shortlist three or four agencies from their work rather than their ads, ask the same 12 questions of each, pay for a small trial project, and sign a contract that leaves you owning your accounts, your data and your content.
It matters because more brands are buying help. In the UK, 46.2% of marketers outsourced part of their marketing in the past year, and social media ad investment grew 17.7% year on year in the first quarter of 2026. A good agency compounds; a poor one costs you a year of feed.
The short version
- Start with a brief, not a search. One page covering goals, audience, platforms, budget and what success looks like makes every pitch comparable.
- Judge the work and the team. Ask who will actually run your account, then meet them. Agency staff turnover in the UK is high.
- Keep pitches small and fair. Three or four agencies, a clear timetable, feedback for everyone, and a paid trial instead of free spec work.
- Own your assets. Ad accounts, pages, data and content should sit in your business accounts, with the agency added as a partner.
- Score, do not guess. Use a weighted scorecard so the decision rests on evidence rather than the best presenter in the room.
What is a social media agency?
A social media agency plans, makes and manages content and campaigns on platforms such as YouTube, TikTok, Instagram and LinkedIn for brands. Services usually span strategy, content production, community management, creator partnerships, paid social and reporting. Many specialise in short form video, creators or paid media, so knowing what you actually need is the first filter.
Do you need a social media agency or an in house team?
Often both. ANA research found 82% of its members have an in house agency, yet 92% still work with external agencies. The UK data points the same way: the most common reason marketers outsource is a skills gap, not cost.
Why UK marketers outsource marketing work (% of those who outsourced)
A useful rule: keep in house what needs daily brand judgement and buy in specialist craft or scale, such as video production, creators and paid optimisation. If you are weighing up video specifically, our guides on video production costs in the UK and choosing a YouTube production company go deeper.
How to choose a social media agency in 7 steps
1. Write a one page brief
Cover the business goal, the audience, priority platforms, budget range, timings, what you will do in house and the three numbers you will judge success by. If you work with creators, borrow the structure from our influencer brief template. A clear brief is the cheapest way to get comparable answers.
2. Build a long list from work, not adverts
Look for agencies whose published work matches your category, platforms and ambition, then check that the results quoted are specific and verifiable. How clients find agencies is changing: an RSW/US survey found networking fell from 73% to 58% and referrals from friends or co workers from 60% to 35% as discovery routes between 2022 and 2025 (US, agency side data).
3. Shortlist three or four and run a fair pitch
Pitching is expensive for both sides. The AAR found that just over half of UK creative agencies spend between £40,000 and £100,000 on a domestic pitch, and media pitch fees are offered in less than 5% of pitches (small sample of 45 agencies). Across Europe, EACA puts the average agency spend at €43,804 per new business pitch. The IPA and ISBA Pitch Positive Pledge asks advertisers to give a written statement setting out why a pitch is necessary and to give every agency feedback. A short list, a fixed timetable and honest feedback get you better answers.
4. Ask every agency the same 12 questions
Use the list below and score every answer the same way. Consistency beats clever questions.
5. Meet the actual team and take references
The IPA Agency Census 2025 counted 24,963 people in member agencies, down 6.8%, and Prolific North reported staff turnover rising to 24.8% in the same census. Ask who will run your account day to day, how long they have been there and what happens if they leave. Then call two current clients, not just the ones on the credentials deck.
6. Pay for a trial project
A paid sprint of four to eight weeks shows how an agency briefs, ships, reports and takes feedback. It is fairer than free spec work and far more revealing.
7. Sign a contract that protects you
Cover scope, deliverables, approvals, fees, notice, ownership of content and accounts, data protection and advertising compliance. Under UK copyright law an assignment of copyright is not effective unless it is in writing, so put ownership of commissioned content in the contract. Our influencer contract template covers the clauses that also apply to creators the agency hires for you.
12 questions to ask a social media agency
| Question | Why it matters | A good answer sounds like |
|---|---|---|
| 1. What would you do in our first 90 days? | Shows whether they listened to your brief. | A specific plan tied to your goals, not a generic deck. |
| 2. Who exactly will work on our account? | The pitch team is not always the delivery team. | Names, roles, time allocation and a chance to meet them. |
| 3. Which results have you delivered for a brand like ours? | Tests relevance and honesty. | Named, verifiable outcomes with context and timescales. |
| 4. How do you decide what to make for each platform? | Reveals whether they think in formats or just repost. | Different ideas for YouTube, TikTok, Instagram and LinkedIn. |
| 5. How will you measure success? | Links activity to business outcomes. | Agreed KPIs, a baseline and a reporting rhythm. |
| 6. How do you price, and what is not included? | Avoids scope creep and surprise invoices. | Clear retainer or project fees with change rates in writing. |
| 7. Who owns the content, accounts and data? | Protects you if you part ways. | "You do. We work as partners in your accounts." |
| 8. How do you handle creators and disclosure? | Both brands and agencies carry ad rule responsibility. | Clear labelling, written briefs and contracts for every creator. |
| 9. How do you use AI, and what do you disclose? | Affects quality, rights and trust. | A written policy covering tools, approvals and IP. |
| 10. What happens when a post goes wrong? | Tests crisis readiness. | An escalation path, response times and named owners. |
| 11. How do approvals and feedback work? | Slow approvals kill social. | Simple stages, deadlines and one source of truth. |
| 12. Why might we not be a good fit? | Honest agencies will tell you. | A candid answer about budget, category or capacity. |
Advertain guidance. Ask every shortlisted agency the same questions and score each answer from 1 to 5.
Questions 7 and 8 deserve extra weight. The CAP Code places primary responsibility on marketers while also expecting agencies involved in preparing ads to follow it, so your agency must know the ASA influencer guidelines inside out.
Who should own your accounts, data and content?
You should. Set up ad accounts, pages and catalogues in your own business manager and add the agency as a partner with only the permissions it needs. Google Ads notes that a linked manager account will not have administrative ownership of the client account by default, and TikTok Business Center lets you select the accounts and assets a partner can access and remove that access. Meta Business Suite works on the same partner principle.
If the agency handles customer data, such as comments, competition entries or lead forms, UK GDPR applies.
“Whenever a controller uses a processor, there must be a written contract (or other legal act) in place.” Information Commissioner’s Office
The ICO guidance lists what that contract must cover, including security, sub processors, audits and what happens at the end of the contract.
How much does a social media agency cost?
There is no reliable UK benchmark for social media agency fees, so be wary of anyone quoting one. What the data does show is how agencies charge. In a global survey of agencies, 85% said they prefer to work on a retainer, and 86% reported an average monthly retainer of $10,000 or less (agency side, USD, vendor research). Gartner found agencies take 20.7% of marketing budgets, and 39% of CMOs planned to cut agency allocations in 2025.
Good relationships last, though tenure varies by agency type and review policy.
Average client agency relationship length (years)
AI is also reshaping the deal. An ISBA survey of 200 UK advertisers found 63% reported some or significant change in content production agency relationships over the past year, in a survey focused on generative AI. Ask how AI efficiency gains show up in your fees.
Red flags when choosing a social media agency
- Guaranteed follower numbers or views, or growth that cannot be traced to real accounts.
- Ad accounts or pages set up in the agency's name rather than yours.
- A senior pitch team you never see again, and no named account lead.
- Case studies with no brand, no dates and no context.
- Reports full of reach and likes with no link to your business goals. Our guide to calculating social media ROI shows what good looks like.
- No written approach to creator disclosure, AI use or data protection.
Agency scoring template
| Criterion | Weight | What to look for |
|---|---|---|
| Strategy and understanding of the brief | 20% | A plan built on your goals and audience |
| Creative quality and platform fluency | 20% | Native ideas for each platform, strong video craft |
| Relevant, verifiable results | 15% | Named work, real numbers, references who confirm them |
| Team and capacity | 15% | Named people, seniority, time allocated, retention |
| Measurement and reporting | 10% | KPIs tied to business outcomes, clear baselines |
| Governance: ownership, data, compliance | 10% | Partner access, processor contract, disclosure process |
| Value and commercial terms | 10% | Transparent fees, break clause, trial period |
Advertain guidance. Score each criterion from 1 to 5, multiply by the weight and add up. Have at least two people score independently.
Once you have chosen, turn the first 90 days into a written plan using our social media strategy template. When we work with brands such as Formula E, where our content passed 7M+ views across YouTube, Instagram and TikTok, the clearest results come from agreeing that plan and its measures before anything is posted. You can see more on our work page or talk to us if you want us on your shortlist.
Frequently asked questions
How do I choose a social media marketing agency?
Brief, shortlist three or four agencies on their work, ask each the same 12 questions, meet the delivery team, take references and run a paid trial before a longer contract.
What questions should I ask a social media agency?
The most revealing are: who will work on our account, what would you do in the first 90 days, how will you measure success, what is not included in the fee, and who owns the content, accounts and data.
How much does a social media agency cost in the UK?
There is no reliable published UK benchmark. Most agencies charge a monthly retainer, with project fees for campaigns and production. Ask for fees broken down by deliverable and for change rates in writing so you can compare like with like.
Who should own the social media accounts when working with an agency?
Your business should. Keep pages, ad accounts and data in your own business accounts and give the agency partner access, so you keep everything if the relationship ends.
