Choose a Google Ads agency by checking three things: how they charge, what they measure, and whether they align their incentives with your profit, not their retainer. The wrong one burns through your budget while sending you vanity reports full of impressions and click-through rates that have nothing to do with revenue.
What does a UK Google Ads agency actually cost?
Most UK agencies charge in one of three ways: a flat monthly retainer, a percentage of ad spend, or a hybrid of both.
| Model | Typical range | When to use |
|---|---|---|
| Flat retainer | £500 to £3,500/month | Stable budgets, clear deliverables |
| % of ad spend | 10% to 20% | Scaling budgets where incentives align |
| Hybrid (retainer + %) | £500 base + 10% | Mid-market businesses growing month on month |
| Performance fee | Rare, usually on leads or revenue | High-trust, long-term relationships |
A percentage model sounds attractive because the agency earns more when you spend more. The problem is that spending more is not the same as profiting more. If your agency pushes to increase budget before your cost-per-acquisition is under control, that is a structural conflict of interest built into the pricing.
A flat retainer removes that conflict but creates another one: the agency earns the same whether they put in ten hours or two. Ask any agency you speak to exactly how many hours per month your account gets, who handles it (senior strategist or junior account manager), and what triggers a strategy review.
There is no single correct model. What matters is that you understand the incentives and that the fee is proportionate to your ad spend. Paying £2,000 a month in management fees on a £2,000 monthly ad budget rarely makes commercial sense.
What Red Flags Should I Watch For?
These are the patterns that consistently signal an agency is optimising for their own retention rather than your growth.
They report on the wrong metrics. If your monthly report leads with impressions, reach, and average position, and buries cost-per-lead or return on ad spend three pages in, that is deliberate misdirection. The only numbers that matter are leads generated, cost per lead, cost per acquisition, and ROAS. Everything else is context.
They own your Google Ads account. Your account, your billing, your data. Any agency that insists on housing your campaigns under their MCC (manager account) and refuses to grant you admin access to your own account is holding your historical data hostage. If you leave, you lose everything. Insist on owning the account from day one.
They promise guaranteed results or specific rankings. No agency can guarantee a cost per click, a Quality Score, or a position on the search results page. Google’s auction changes constantly. Anyone making specific guarantees does not understand platform limits.
They use broad match on everything from day one. Broad match keywords without solid negative keyword lists and conversion data behind them will burn through budget on irrelevant searches in the first few weeks. It can work as a strategy later, once the account has data, but it should never be the default starting point.
They cannot explain their bidding strategy in plain English. If you ask why they are using Target CPA instead of Maximise Conversions and they cannot give you a clear, commercially grounded answer, they are not thinking about your account strategically. They are letting the algorithm do the thinking for them.
Long contracts with no performance clause. A 12-month lock-in with no break clause based on performance is not a partnership. It is a guarantee of revenue for them regardless of what happens to yours. Three months is a reasonable minimum to see results. After that, monthly rolling or quarterly reviews are standard in well-run agencies.
They do not ask about your margins. If an agency sets up your campaigns without knowing your gross margin, your average order value, or your acceptable cost per acquisition, they have no way to optimise toward profit. They are optimising toward clicks and hoping for the best.
What Does a Good Google Ads Agency Actually Do?
Before touching the account they should want to know: what does a customer cost you to serve, what is their lifetime value, what is the maximum you can pay to acquire one and still make money. That number, your target CPA or breakeven ROAS, drives every decision from bidding strategy to budget allocation to which campaigns to pause.
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Get Your Free Growth Plan →In the first 30 days, expect an audit of the existing account if there is one, clarity on conversion tracking (is it actually recording the right events), campaign restructuring or build-out, and agreement on what success looks like at 30, 60, and 90 days.
Ongoing, a good agency does the following:
- Reviews search term reports weekly and adds negatives proactively
- Tests ad copy systematically, not randomly, with a hypothesis for each test
- Monitors Quality Scores and landing page relevance, not just to improve scores but because low scores signal a mismatch between the ad and what the user actually wants
- Reports on revenue and leads first, platform metrics second
- Flags budget changes before making them, not after
- Tells you when the account is plateauing and why, and has a view on what to do about it
A good agency flags when Google Ads has reached its ceiling for your business at current margins, or that your landing page is the reason conversion rates are low, or that your offer is not compelling enough to compete at your target CPA. An agency that only ever wants to increase budget without addressing conversion fundamentals is not a strategic partner.
How Do I Evaluate an Agency Before Signing?
Ask these questions in your first call. The quality of the answers tells you more than any case study.
1. Who actually works on my account day to day, and what is their experience level?
Agencies win clients with senior people and service them with juniors. Ask for the name and background of the person who will own your account.
2. Can I see an example of a search term report and how you acted on it?
This is operational. A confident, experienced agency can walk you through a real example without breaking client confidentiality by redacting identifying details. If they cannot, they are not doing this work properly.
3. How do you handle conversion tracking setup, and who owns that process?
If they say “we work with whatever you have set up,” that is a problem: conversion tracking is the foundation, and an agency that does not own this process will optimise toward bad data.
4. What does a typical monthly report look like, and can I see a redacted example?
If they cannot show you or talk you through the format, you do not know what you are buying.
5. What is your policy on account ownership?
The answer should be immediate and unambiguous: you own the account, they manage it.
6. What results have you driven for businesses similar to mine?
Reasonable agencies will share directional numbers without naming clients, with an answer like: “We worked with a B2B SaaS company on similar budgets and brought CPA down from £180 to £95 in three months by restructuring match types and improving landing page relevance.” If they cannot get that specific, treat the case studies as marketing rather than evidence.
Should I Use a Specialist Agency or a Full-Service One?
For Google Ads specifically, a specialist usually outperforms a generalist at the same price point. Generalist agencies spread their talent across SEO, social, email, and paid search. A Google Ads specialist has people who live inside Google Ads every day, track platform changes as they happen, and have pattern recognition across dozens of accounts in similar categories.
However, if you need joined-up tracking across channels, a specialist may require more coordination on your side to connect paid data with organic and email performance. Coordination is the tradeoff, and disconnected channel data is one of the most common reasons businesses misattribute leads and make poor budget decisions.
If you need both Google Ads and wider marketing systems under one roof, look for an agency where those disciplines are genuinely integrated, not siloed teams under the same brand name.
What Should I Do Before Hiring Anyone?
Before you brief any agency, do three things.
First, get admin access to your own Google Ads account if you have one. If someone else owns it, recover it now. Go to Google Ads, open the Admin menu, select Access and security, and ensure your own email has admin rights.
Second, install Google Analytics 4 properly and confirm that your key conversion events are tracking. You cannot evaluate an agency’s work without baseline data.
Third, know your numbers. What is your average order value or contract value? What gross margin does the business run at? What is the maximum CPA that still leaves you profitable? If you do not know these going in, an agency has no anchor to work from and neither do you.
FAQ
How long should I give a Google Ads agency before judging results?
Allow three months minimum for a new account build, assuming conversion tracking is correct from the start. In months one and two the account is gathering data. Meaningful optimisation and cost reduction typically shows from month three onwards. If conversion volumes are very low, allow up to six months before drawing conclusions, but expect clear directional progress and transparency about what is being learned.
What is a reasonable Google Ads management fee for a small UK business?
For a business spending £1,000 to £5,000 per month on ads, expect to pay between £500 and £1,500 per month in management fees, depending on account complexity and how active the campaign management is. As a rule of thumb, fees above 30 to 40% of ad spend rarely make sense at lower budgets.
Can I run Google Ads myself instead of using an agency?
Yes, though the risk is wasted spend during the learning phase and ongoing suboptimal performance from not having cross-account pattern recognition. Many business owners find that managing Google Ads properly takes more time than expected, and as a rough guide, once budgets exceed around £2,000 per month the opportunity cost of doing it yourself tends to outweigh agency fees.
What should I do if my current agency is not performing?
Request a plain-English breakdown of your CPA and ROAS trends over the past 90 days. If they cannot provide it or the numbers show no improvement, give written notice of your intention to leave and immediately secure admin access to your account before changing anything else. Take an export of your campaign history, search term data, and any audience lists before the relationship ends.
Is a Google Partner badge a reliable quality signal?
Partially. Google Partner status requires meeting a spend threshold across managed accounts, maintaining a minimum optimisation score, and holding platform certifications. It does not guarantee good strategy or honest account management. Ask what the badge means to the agency and how they use it internally. An agency that leads their pitch with the badge rather than their methodology is telling you something.
