UK PPC Agency: The Ultimate Vetting Framework

I see this question all the time, and the frustration is completely understandable. The market is flooded with "PPC agencies" in the UK, and most of them are peddling the same generic promises. The truth is, finding a genuinely effective agency isn't about luck or stumbling across a hidden gem. It's about having a rock-solid process to cut through the noise and identify true expertise.

The problem isn't that there are no good agencies. The problem is that most business owners don't know how to properly vet them. They look at flashy websites and vague case studies, get sold on a smooth discovery call, and then wonder why their ROAS is stuck in the mud six months later. You need to flip the script. Instead of being sold to, you need to become an expert evaluator. This guide will give you the framework to do just that.

First things first: do your homework before you even type "PPC agency UK" into Google

Before you waste a single minute on a call with an agency, you need to have a handle on your own business metrics. If you don't know your numbers, you're flying blind, and any agency can pull the wool over your eyes with vanity metrics like 'impressions' and 'clicks'. The two most critical things to define are your real customer profile and your customer lifetime value.

Forget the generic profiles. "Companies in the finance sector with 50-200 employees in London" tells you nothing of value and leads to bland ads that get ignored. You need to get under their skin. What is the specific, expensive, career-threatening nightmare that keeps your ideal customer awake at night? Your service or product is the aspirin to that headache.

For example, if you sell compliance software, the nightmare isn't 'needing to manage regulations'; it's 'the CTO being personally liable for a multi-million-pound data breach fine.' If you're a B2B service, the pain isn't 'needing more leads'; it's 'the founder being three months away from missing payroll because the sales pipeline is dry.' This isn't just marketing fluff; it's the foundation of any succesful ad campaign. An agency that doesn't push you to define this level of detail in the first call doesn't understand how to actually acquire customers.

The real question isn't "How low can my Cost Per Lead go?" but "How much can I afford to pay to acquire a great customer?" The answer is your LTV. If you don't know this, you can't possibly judge if an agency's performance is good or bad. A £50 lead might seem expensive, but if that customer is worth £5,000 to you, it's an absolute bargain.

Here’s the basic maths:

LTV = (Average Revenue Per Customer Per Month * Gross Margin %) / Monthly Churn Rate

Let's make this practical. Use the calculator below to figure out your own LTV and what you can realistically afford to spend to get a new customer. This number will be your north star when evaluating any agency's proposals and results.

How to properly vet an agency's case studies (and not get fooled)

Once you know your numbers, you can start looking at agencies. The first thing you'll see is their case studies. This is where most people get it wrong. They see a headline like "Generated £100k for Client X" and get impressed. That number is meaningless without context.

You need to dig deeper. Look for case studies that are highly relevant to your business. Are they in the same niche? Are they selling a similar product or service (e.g., B2B SaaS vs. B2C eCommerce)? Did they use the ad platforms you want to use? A great result on Meta Ads for an eCommerce brand doesn't mean they can get you £50 leads on LinkedIn for your high-ticket consulting service. I remember one client, a medical job matching platform, came to us with a £100 CPA. We got it down to £7, but that was because we had deep experience in both SaaS and recruitment. That kind of niche expertise is what you're looking for.

Here’s a simple flowchart to guide your evaluation. If you can't tick the boxes, the case study is probably irrelevant to you.

The first call is an audit, not a sales pitch

This is the most important step. A good agency will use the initial call to demonstrate their expertise, not just to qualify you as a lead. Many offer a free initial consultation or account review, and you should take full advantage of this. This is your chance to see how they think. Tbh in paid advertising, you can't really promise anything as it's impossible to predict how exactly the ads will perform. If they start making wild promises about doubling your ROAS, run.

Instead, you want them to ask you tough questions about your business, your customers, and your numbers (which you now have!). You want them to look at your existing ad account (if you have one) and give you specific, actionable advice right there on the call. What would they change first? What audiences have you missed? What's wrong with your ad creative?

Here are some questions to ask them to separate the experts from the salespeople:

• -> "Based on what you've seen, what's the single biggest opportunity for improvement in our account?"
• -> "Walk me through a campaign for a client similar to us that *didn't* work at first. What went wrong and how did you fix it?" (This tests honesty and problem-solving skills).
• -> "What metrics will you be focusing on for us beyond ROAS, and why?" (The answer should involve your LTV:CAC ratio).

If they are cagey, speak in vague generalities, or try to deflect until you've signed a contract, they either don't know the answer or they don't have your best interests at heart. A true expert is always willing to give away some value for free, confident that it will demonstrate their worth.

Does their location in the UK even matter?

In short, no. Not really. I see lots of people searching for a "PPC agency in London" or "Manchester," thinking a local agency will somehow be better. Unless you're a local service business that needs in-person meetings (and even then, it's debatable), location is one of the least important factors. We work with clients all over the world from our UK base.

What is infinitely more important is their expertise in your market and niche. Do they understand the nuances of the UK consumer? Do they have experience with the specific challenges of your industry within the UK? That's what matters. A specialist B2B SaaS agency based in Glasgow will do a far better job for a London-based fintech startup than a generic "do-it-all" agency based in Shoreditch. Don't let geography limit your options; prioritise expertise above all else.

What's the final piece of the puzzle?

After all the vetting, the numbers, and the calls, it often comes down to a simple gut feeling. Do you trust these people? Do you feel like they genuinely understand your business and are invested in your success? Paid advertising is a partnership. There will be campaigns that don't work, and you need to be able to have honest, productive conversations when that happens.

Tbh if someone asks us for references to call one of our clients after they've already reviewed our detailed case studies and we've spent an hour auditing their account for free, it's an instant red flag for us. It signals a fundamental lack of trust that will probably poison the relationship from the start. After you've done your due diligence, you have to be ready to make a decision and trust the process.

Choosing an agency is a big decision, and it's right to be cautious. But by following a structured vetting process, you can dramatically increase your chances of finding a partner who will become a genuine driver of growth for your business.

I've detailed my main recommendations for you below:

Ultimately, a great agency should feel like an extension of your own team, not just a vendor. They should be as obsessed with your business metrics as you are. If you’re struggling to find that partner or just want a no-nonsense second opinion on your current advertising efforts, consider booking a free, no-obligation strategy session with us. We’ll dive into your account and give you an honest assessment of what's working, what isn't, and what we'd do to improve it.

Hope this helps!