How to Choose an SEO Agency: What to Look For and What to Avoid

Choosing an SEO agency comes down to three things, which are evidence that it can deliver in a market like yours, a method that follows Google’s guidelines and reporting that ties search visibility to leads and revenue. This guide sets out what to look for in an SEO agency, the questions worth asking and the warning signs that tend to lead to wasted budget. It is written for marketing and business leaders at UK organisations comparing providers and it draws on how we deliver SEO services for B2B organisations across technology, healthcare, professional services and the public sector.

The wrong choice is expensive in ways that are not obvious at first. Poor link building or thin content can take months to unwind and an agency that reports on traffic alone can spend a year on activity that never reaches the sales pipeline.

What to Look for in an SEO Agency

A good SEO agency understands your commercial goals, explains its method in plain English and can show sustained results for organisations similar to yours. The criteria below are the ones most worth testing during the selection process. For websites built on WordPress, our article on hiring a specialist WordPress SEO partner adds platform-specific checks.

1. Relevant results in your sector, at a similar scale and with similar goals.
2. Technical competence, shown through a clear audit method.
3. A content approach built around search intent rather than volume.
4. Link acquisition that stays within Google’s spam policies.
5. A plan for visibility in AI search as well as traditional results.
6. Reporting tied to leads, pipeline and revenue.
7. Transparency over who does the work and what changes are made.

Most agencies will claim strength in all seven areas during a pitch. The useful test is asking how each would apply to your website and sales process, then comparing the depth of the answers.

Define Your Goals Before You Compare Agencies

The right agency depends on what you need SEO to achieve, so it pays to agree your goals internally before speaking to anyone. A regional business competing for local searches faces different problems from a national retailer or a B2B firm targeting a narrow group of decision-makers and agencies tend to be stronger in some of these areas than others.

Timescales also shape the choice, because SEO builds over months rather than weeks. Our guide to how long SEO takes to work explains the factors that affect it. If a product launch or a website rebuild is due, an agency should be able to explain what can be achieved before that date and what will take longer.

Consider your internal capacity too. Some organisations have writers and developers who can implement recommendations, while others need an agency that handles content, technical changes and reporting itself. If you are still deciding between building a team and outsourcing, our comparison of an SEO agency versus in-house SEO covers the trade-offs in more detail.

Your website platform is the final consideration. We specialise in WordPress because it gives us direct control over Core Web Vitals, schema, internal linking and content structure and on other platforms we provide content strategy, technical audits and AI search optimisation with implementation handled by the client’s own team. Any agency you speak to should be equally clear about what it can and cannot change on your platform.

Look for Evidence in Markets Like Yours

Case studies are most useful when they come from organisations with a similar size, sector and sales cycle to your own. A strong result for a consumer brand tells you little about how an agency would handle a B2B firm with a long buying process and a small pool of high-value search terms.

Growth in qualified enquiries, pipeline or revenue is a stronger signal than a spike in visitors and results sustained over a year or more say more about method than a short-term gain after a single fix. Where clients cannot be named, ask for anonymised data and a reference you can speak to about how the agency worked.

Technical Competence and a Clear Method

Technical SEO is the foundation that content and authority building depend on, so an agency should be able to explain how it audits a website and prioritises what it finds. That includes crawlability, indexing, site architecture and structured data, along with how JavaScript rendering and server configuration affect visibility.

Page experience is one area where depth shows quickly. Google describes Core Web Vitals as a set of metrics that measure real-world loading performance, interactivity and visual stability and recommends that website owners achieve good scores. Ask how an agency would diagnose a poor score and who would make the code changes, because a recommendation that nobody implements has no effect. Within our technical SEO services, a senior web developer handles schema, page speed, Core Web Vitals and the code changes on every account.

A trial audit is a reasonable request during the selection process. Google’s guidance on whether you need an SEO advises granting only read access to Search Console at this stage and says an audit should give realistic estimates of improvement and the work involved. It also notes that third-party tools do not have access to Google’s internal ranking data, so an agency’s recommendations should be checked against official Google documentation.

An understanding of accessibility is a further advantage. Many of the changes that help search engines interpret a page, such as a clear heading structure, descriptive link text and meaningful alt text, also support the Web Content Accessibility Guidelines. That matters for public sector bodies and for any organisation that wants its website to work for every visitor.

Content, Links and Google’s Spam Policies

An agency’s approach to content and links shows whether it is building long-term value or chasing short-term movement. Google’s ranking systems are designed to prioritise helpful, reliable, people-first content created to benefit readers rather than to manipulate rankings, so content plans should start from audience research and search intent rather than a list of keywords to repeat.

Ask how the agency researches topics, who writes the content and how subject experts within your organisation are involved. In B2B and regulated sectors, content often needs specialist input to be accurate and a good agency builds that review into its process rather than publishing generic copy at volume.

Link building needs the closest scrutiny. Google’s spam policies define link spam as creating links primarily to manipulate search rankings and list buying or selling links, excessive link exchanges and automated link creation as examples. An agency that promises a fixed number of links each month, or will not say where its links come from, may be exposing your website to that risk.

Agencies that create content other publications want to cite tend to build authority that lasts. The distinction that matters is whether links are earned on merit or acquired through arrangements Google treats as manipulation.

Visibility in AI Search and Google’s AI Features

An SEO agency should be able to explain how it plans for visibility in AI-generated answers as well as traditional search results. Google states that there are no additional requirements to appear in AI Overviews or AI Mode and that the same foundational SEO practices apply, so strong organic SEO remains the basis for visibility in Google’s AI features.

Other platforms add a further layer. ChatGPT, Copilot, Gemini and Perplexity now answer many queries that previously needed a click to a website and generative engine optimisation (GEO) and answer engine optimisation (AEO) focus on structuring content so these tools can understand and cite it. Our AI SEO services work alongside organic SEO for this reason, structuring content and site architecture for visibility in both traditional results and AI-generated answers.

Be cautious of any agency that sells AI search as a separate product built on special techniques. Google’s guidance on hiring an SEO suggests checking whether advice on AEO or GEO aligns with its official documentation, a sensible test for any proposal built on new terminology.

Reporting, Communication and Who Does the Work

Good reporting explains what changed, why it changed and what happens next, in terms your leadership team would recognise. Rankings and traffic are useful indicators, but a report should connect them to conversions, enquiry quality and pipeline wherever the data allows.

Every SEO retainer client of ours has access to the Priority Pixels reporting dashboard, which brings Google Analytics, Search Console, conversion tracking and Core Web Vitals together in one place. We then hold a monthly call to walk through the SEO roadmap, so progress is discussed openly rather than left in a document nobody reads.

Ask every agency who will work on your account day to day and what happens if that person leaves. On our accounts, the SEO lead writes the monthly plan and sets priorities, a website and SEO specialist handles on-page work and a senior web developer makes the technical changes. Clearly defined roles mean work continues when individual team members are away.

Red Flags When Choosing an SEO Agency

Some warning signs appear early in the sales process and tend to predict a difficult relationship. The same Google guidance states that no one can guarantee a first place ranking on Google and warns against SEOs who claim a special relationship with Google or are secretive about what they intend to do.

Long contracts with no review points are another reason for caution. Google’s guidance also points out that you remain responsible for the actions of any company you hire, which is why transparency matters as much as expertise.

How Much Does an SEO Agency Cost

SEO agency costs vary widely and the price depends on the scope of work, the competitiveness of your market and how much the agency implements itself. Most ongoing SEO is priced as a monthly retainer, because results build over months and the work needs consistent attention. Our guide to evaluating professional SEO services covers how to compare scope before you commit.

Project fees are common for defined work such as an audit, a migration or a technical fix and some organisations combine the two. Performance-based pricing exists but is harder to structure fairly, since rankings and traffic are influenced by factors outside either party’s control.

The cheapest proposal is rarely the lowest-cost option once wasted months are counted. Compare what each proposal includes, who will deliver it and how success will be measured. Our guide on measuring ROI from your SEO agency sets out how to judge value once the work is under way.

Questions to Ask Before You Sign

The most useful questions ask an agency to explain how it would work on your website rather than describe its services in general. A capable agency answers in specifics and asks its own questions about your business, competitors and customers.

Google’s guidance on hiring an SEO includes several of the questions below and the rest come from the areas covered above. Using them as a consistent checklist makes it easier to compare proposals fairly.

• Can you show results for organisations similar to ours in size and sector?
• Do you follow Google Search Essentials and how do you check your advice against it?
• What would you look at first on our website and why?
• What results would you expect and over what timeframe?
• How do you measure success beyond rankings and traffic?
• Who will work on our account and how will we communicate with you?
• Will you share every change you make and the reasoning behind it?
• How do you approach AI search visibility alongside organic SEO?

An agency that answers these clearly and is willing to put its method and reporting in writing, is usually a safer choice than one that leads with promises. The aim is a partner that understands your commercial goals and can show steady progress towards them over time.