How to Choose a Google Ads Agency: What to Expect and What to Ask

Choosing a Google Ads agency comes down to one test: will it prove, every month, that the money you give Google is turning into enquiries or sales? Everything else in a pitch is detail. Before you compare proposals, it helps to know what you’re actually buying. In the UK you pay two separate bills: the ad spend that goes to Google, and a management fee to the agency, which Whito’s 2026 research on UK PPC costs puts at £300 to £2,000 a month for most businesses. The right agency agrees what a lead or sale is worth to you before a single ad goes live, then reports against that number. This guide covers what the work involves, what to budget, how agencies price it and the questions that separate a good partner from an expensive habit. Use it to judge any shortlist, our own Google Ads agency team included.

TL;DR

• A Google Ads agency handles strategy, build, tracking, weekly optimisation and reporting, so your budget goes on the searches most likely to convert.
• Ad spend and management fees are separate. Google’s own policy says an agency must tell you about its fee in writing and show it on invoices.
• Most UK small businesses pay £1.50 to £2.50 a click, according to Whito, but legal and finance clicks cost several times that.
• Judge agencies on the KPI they commit to, whether you own the account, how they report and whether they’ve worked with businesses like yours.
• Hiring makes most sense once your spend and lead values are high enough for a few points of efficiency to pay the fee.

Table of Contents

• What does a Google Ads agency actually do?
• What should you budget for?
• How do agencies price Google Ads management?
• How to choose a Google Ads agency
• Is it worth hiring an agency to manage Google Ads?
• Questions to ask before you sign
• Our perspective
• Talk to our Google Ads team
• FAQ
• Sources

What does a Google Ads agency actually do?

An agency takes responsibility for the whole paid search process: the thinking before launch, the build, the week-to-week management and the reporting that proves what happened. Most businesses hire one because Google Ads punishes neglect. Search terms drift, competitors change their bids and an account left alone for a quarter usually ends up paying more for less.

The work falls into three rhythms.

Before launch: goals, audit and build

A good first meeting is about money, not keywords. The team should want to know what a customer is worth to you, what you can afford to pay for one, and which products, services and postcodes matter most. Only then do they:

• audit any existing account for wasted spend and broken tracking;
• research keywords and the intent behind them, separating people ready to buy from people idly comparing;
• choose campaign types (Search, Shopping, Performance Max) to suit how you sell;
• write ads, add assets and build negative keyword lists so you stop paying for irrelevant searches;
• set budgets, locations and audiences;
• install conversion tracking so Google Ads records real enquiries, calls and orders.

Tracking is the step people skip and regret. Google’s bidding works out who to show your ads to from the conversions you feed it. If it’s counting page views or newsletter sign-ups as “conversions”, it’ll happily go and find you more of those.

Every week: search terms, bids and tests

Once the account is live, the agency reads the search terms report, adds exclusions, adjusts bids and budgets, tests new ad copy and checks that conversion data is still flowing. For ecommerce brands it also means work on the product feed, because Shopping performance leans heavily on titles, categories and images. And somebody has to look at the landing page. Better ads pointing at a page that doesn’t convert just buy you more disappointed visitors.

Every month: reporting you can act on

A monthly report shouldn’t be a wall of impressions and click-through rates. It should say what changed, what was learned and what happens next, in leads, cost per lead, orders and revenue. If you can’t connect the report to money in the bank, it isn’t doing its job.

What should you budget for?

You’ll pay two things, and mixing them up is the most common budgeting mistake.

• Ad spend is what Google charges for clicks. It goes to Google, not the agency.
• The management fee pays the agency for strategy, build, optimisation and reporting.

Google insists they’re kept apart. Under its third-party policy, an agency that charges a fee on top of Google Ads costs must tell new customers in writing before the first sale and show the fee on invoices. Where it sends monthly performance reports, the cost shown must be the exact amount Google charged, without the agency’s fees mixed in. A quote of “£2,000 a month, all in” that won’t say how much reaches Google is a red flag.

What the clicks cost

Whito’s research says most UK small businesses pay £1.50 to £2.50 a click, with legal services the dearest sector at roughly £8.25 and retail and ecommerce nearer £0.95. Treat those as a guide. Whito is upfront that no primary UK-wide survey of Google Ads click costs exists, so its sector figures are indicative estimates rather than hard statistics.

Daily budgets also behave differently from how most people expect. Google can spend up to twice your average daily budget on a busy day, but you won’t be charged more than your daily budget multiplied by 30.4 over a month. So set £50 a day and a Tuesday might cost £90 while Wednesday costs £20. Your monthly ceiling is still £50 × 30.4 = £1,520.

What the management costs

The same Whito research puts typical UK agency management fees at £300 to £2,000 a month on top of ad spend. It splits that further: freelancers at around £200 to £800 a month, agencies handling smaller budgets at £500 to £1,500, and agencies running mid-sized budgets at £1,500 to £5,000. Where fees are charged as a percentage, it gives 5 to 15% of spend, usually for budgets above £5,000 a month.

Here’s why the fee on its own tells you very little. Take an illustrative account spending £3,000 a month at £1.80 a click, which buys roughly 1,670 clicks. At a 4% conversion rate that’s about 67 leads. Add a £600 management fee and the total cost per lead is roughly £54. If better search-term control and a sharper landing page lift conversion to 5%, the same spend brings about 83 leads and the cost per lead drops to around £43. The fee didn’t change. What it bought did.

How do agencies price Google Ads management?

Four models cover almost every proposal you’ll see. None is automatically better; each rewards the agency for something slightly different, so it’s worth knowing what you’re encouraging.

Flat monthly fee

• How it works: a fixed amount for a defined scope of work.
• Suits: businesses that want predictable costs and a stable budget.
• Watch for: a scope so vague that “management” turns out to mean a monthly login.

Percentage of ad spend

• How it works: the fee is a share of what you spend with Google each month.
• Suits: larger accounts that are scaling and need more work as they grow.
• Watch for: the built-in temptation to recommend higher budgets. Ask how they’d decide to cut spend.

Hourly or project rate

• How it works: you pay for time or for a defined piece of work.
• Suits: audits, rebuilds, tracking fixes and one-off campaigns.
• Watch for: projects that end at launch, just when the account needs the most attention.

Performance-linked fee

• How it works: part of the fee depends on agreed results, such as a cost-per-lead target.
• Suits: lead generation with clean tracking and an agreed definition of a qualified lead.
• Watch for: arguments about what counts. Write the definition into the contract.

Whichever model you choose, the useful question isn’t “what’s the cheapest fee?” but “what will each pound of total spend bring back?” For a deeper breakdown of fees, see our guide to Google Ads management cost in the UK.

How to choose a Google Ads agency

There are thousands of agencies in the UK, from one-person freelancers to big networks. These five checks narrow the field quickly.

Agree one primary KPI before launch

The agency should commit to one headline measure. For ecommerce that’s usually return on ad spend (ROAS): revenue from the campaigns divided by ad spend. For lead generation it’s cost per lead or cost per acquisition, ideally refined by lead quality. Conversion rate, impression share and budget pacing support the headline number; they don’t replace it.

ROAS is only as honest as the data behind it, so conversion values need to be right and brand searches reported separately from non-brand. People already searching for your name were coming anyway. Read results as a trend across several months rather than judging one good or bad month.

Know what the Google Partner badge means

Google Ads certifications belong to individuals, and Google says each one stays valid for a year before it has to be retaken. One certified employee doesn’t make the company a Partner. To earn the badge, Google’s Partner requirements ask for a minimum optimisation score of 70%, $10,000 of ad spend across managed accounts over 90 days, and at least half of the company’s account strategists certified. Premier Partners must also sit in the top 3% of participating companies in their country each year.

So the badge tells you an agency manages a reasonable volume of spend and keeps its people trained. It doesn’t tell you whether they understand your market. Useful signal; not a verdict.

Make sure you own the account

Google’s guide to working with third parties says you have a right to know, at minimum, the clicks, impressions and cost of your ads, and that you should get your agreement in writing. It also says the agency must set up a separate Ads account for you. Insist that the account sits in your name with you as an admin, so your campaign history, conversion data and audiences stay yours whoever manages them.

Match their experience to how you sell

Ecommerce, B2B lead generation and local services behave very differently in Google Ads. A team that’s brilliant at Shopping feeds may be clueless about a six-month B2B sales cycle. Ask for examples from businesses like yours, and ask them to explain, in plain English, how they’d approach your first 90 days.

Ask who joins up the rest of the funnel

Paid search rarely works alone. Landing pages, tracking, SEO and your other channels all decide how far the budget stretches. An agency with development, content and analytics skills in-house avoids the week-long delays that come from emailing changes between three suppliers.

Is it worth hiring an agency to manage Google Ads?

For many UK businesses, yes. It’s most clearly worth it when:

• your market is competitive, so small gains in efficiency decide who wins the click at a price you can afford;
• your time is worth more elsewhere, because proper management means weekly search-term reviews, testing and reporting;
• you’re scaling spend, and a few percentage points of efficiency on a bigger budget are worth real money;
• you sell online, where feeds, Shopping and Performance Max reward specialist knowledge;
• you need accountability, with a reporting rhythm that shows what each pound produced.

And sometimes it isn’t. If you’re spending a few hundred pounds a month, a full agency retainer can eat a big slice of the budget before a single click is bought. A capable freelancer, or a one-off audit and set-up that you then run yourself, may make more sense until spend and lead values grow. We go into the case for and against in five reasons to hire a Google Ads agency.

Questions to ask before you sign

Take this list into every pitch meeting. A proposal that answers all of it clearly is a decent starting point; one that dodges two or three is telling you something.

• Goals: what’s the primary KPI, and what’s the target?
• Scope: does the fee cover set-up, ongoing optimisation, tracking, reporting and landing page advice?
• Ownership: is the Google Ads account in my name, with admin access for me?
• Fee disclosure: is the management fee shown separately from ad spend on every invoice?
• Reporting: how often, in what format, and does it show leads and revenue rather than clicks?
• People: who actually manages the account day to day, and how often will I speak to them?
• Terms: what’s the minimum term and notice period?
• Budget: is the recommended spend realistic for my cost per click and target cost per lead?

Our perspective

Most of the accounts we’re asked to look at don’t fail because of some clever trick the agency missed. They leak money in dull places: broad keywords with no negative list, tracking that counts the wrong things, and landing pages nobody has touched since launch. That’s why we’d always pick the agency that obsesses over the boring fundamentals over the one with the slickest dashboard.

We’re also wary of judging Google Ads in isolation. Customers now find businesses through Google results, AI Overviews, ChatGPT and Gemini, often within the same buying journey. The research that tells you which questions buyers ask improves your ads, your landing pages and your chances of being cited in AI answers all at once. If that’s new territory, our guides explain what AI SEO is and how GEO differs from SEO.

So we run Google Ads alongside SEO, GEO and AEO with one in-house team, and we report against enquiries and revenue rather than activity. When a campaign needs tightening, you see what we changed and why. When it’s working, you see where we’d scale next. Paid search used to be a channel you could hand to a specialist and forget about. It isn’t any more, and an agency that still treats it that way is selling you last decade’s service.

Talk to our Google Ads team

Castle is a UK marketing agency founded in 2014. Google Ads sits within a wider service that also covers Meta Ads, TikTok Ads, ChatGPT Ads, ecommerce marketing, lead generation, SEO, GEO and AEO, so budget can move to wherever it earns most. If you’re generating leads rather than selling online, our advice on choosing a lead generation agency shows where paid search fits in a wider enquiry pipeline.

Browse thefull list of services, or meet our regional teams in Manchester, Liverpool and Lancashire. Tell us your target cost per lead or ROAS and we’ll tell you honestly whether we think it’s achievable.

Book a call with our PPC team

FAQ

How much does a Google Ads agency cost in the UK?

Most UK businesses pay a management fee of £300 to £2,000 a month on top of ad spend, according to Whito’s 2026 cost research. Larger or more complex accounts cost more. Ask for the fee and the recommended ad budget to be set out separately.

What’s the difference between ad spend and a management fee?

Ad spend is paid to Google for clicks on your ads. The management fee pays the agency for strategy, build, optimisation, tracking and reporting. Google’s policy requires agencies to disclose a separate fee in writing and show it on invoices.

Should the Google Ads account be in my name?

Yes. Owning the account means you keep your campaign history, conversion data and audiences whoever manages them. A transparent agency works inside your account and gives you admin access.

Does a Google Partner badge mean an agency is good?

It means the company meets Google’s thresholds for optimisation score, managed spend and staff certification. That’s a useful signal of scale and training, but it says nothing about whether the team understands your sector, so check case studies too.

How long before Google Ads delivers results?

Ads can bring traffic within days of launch, but the first few weeks are for learning and refinement. Judge an account on several months of data, read as a trend, rather than on its first month.

Sources

• Whito: Google Ads Cost UK 2026, How Much PPC Really Costs
• Google Advertising Policies Help: Third-party policy
• Google Advertising Policies Help: Working with a third party
• Google Ads Help: About average daily budgets
• Google Ads Help: About Google Ads certifications
• Google Ads Help: How to become a Google Partner or Premier Partner

Recommended

• Google Ads Management Cost: What UK Businesses Pay and Why
• 5 reasons you need a Google Ads agency to run Google Ads for your business
• How to choose a digital marketing agency in the UK (and what to avoid)