Technical SEO providers: which sources to check

What to take away

Why evidence beats a badge list

Start with inclusion criteria, not names

A listicle works when the reader knows what qualifies for entry. Write down the country you are buying in, the contract size and the minimum evidence you will accept. A provider serving England only is a different proposition from one covering the whole UK. Record the criteria in a shared file so two buyers score the same way.

Geography changes the evidence base. A contract that includes Scotland, Wales or Northern Ireland may need added checks on data handling and accessibility across four nations. Data protection is governed by the UK GDPR and the Data Protection Act 2018, and the Information Commissioner's Office is the regulator to search for enforcement action and guidance. Weighting is a decision, not a default, so write it down before scoring begins.

Separate public records from marketing claims

Marketing pages describe intent. Public records describe history. Companies House publishes governance information about its own board and committees, which is a useful model for the kind of corporate transparency you can check on a supplier. Read the governance page to see what a regulator treats as disclosable.

Technical SEO work usually starts with a crawl, a log-file review and a template audit. The source types below help you judge whether a provider can evidence that work rather than describe it.

Three source types to check before shortlisting

Corporate and regulatory records

Check the supplier's registered entity, filing history and any adverse regulatory findings. Search the Companies House register by company name or company number to confirm the entity, its accounts and any overdue filings. The Advertising Standards Authority maintains a list of non-compliant online advertisers, which is relevant when a provider makes performance claims in its own advertising.

Filing history shows how long an entity has traded and whether accounts are overdue. Overdue accounts are a fact, not a judgement.

Accessibility and standards conformance

Anyone auditing templates, navigation or forms will touch accessibility. In the UK the duties come from the Equality Act 2010, and public sector bodies are covered by the Public Sector Bodies (Websites and Mobile Applications) Accessibility Regulations 2018. The W3C's WCAG conformance FAQ explains what a conformance claim does and does not mean, which helps you judge whether a supplier's accessibility language is precise or decorative.

Ask which conformance level the supplier claims, and on which templates. A claim without a scope is hard to score.

Ask which crawling and diagnostic tools the provider works with — Screaming Frog, Sitebulb or a cloud crawler — and who keeps the crawl data, the log files and the Google Search Console access when the engagement ends.

Commercial terms and references

Ask for two references from clients of a similar size. Ask what the provider changed and what happened next. If references are refused, treat that as data, not as a rejection of the provider.

Also ask for the standard contract, the notice period and who owns the audit files at the end.

Worked example: scoring three fictional suppliers

Suppose a team in Manchester has a budget of £2,500 a month for a six-month engagement. Three illustrative suppliers are scored out of five on evidence quality.

Supplier A totals 17, Supplier B 14 and Supplier C 14. On that evidence, Supplier A advances to a paid discovery phase of £2,500 for one month. The other two are asked for a written method before any money moves. The weights behind this example are illustrative, chosen by the buyer before scoring began.

How to run the scoring session

Hold the session before proposals arrive. Agree weights, then score. If a criterion cannot be evidenced, record a zero rather than an average. This keeps the comparison honest and makes the final decision defensible to finance. Keep the scoring sheet with the proposals so an auditor can follow the trail.

What to do when evidence is thin

Thin evidence is common with smaller suppliers. In that case, buy a small paid discovery phase rather than a full contract. Cap it in writing. Our guide to agency review data and sources explains how to structure that evidence request.

Common questions

Should I rank providers in an internal document?

No. Rank criteria, not companies. Score each supplier against the same weighted criteria and let the totals order themselves.

Which geography should the criteria cover?

Use the geography of the work. If the contract covers England only, say so. If it covers Scotland, Wales or Northern Ireland too, the evidence standard should be the same across all four nations.

How many providers should I score?

Three to five is workable. Fewer than three gives you no contrast. More than five usually means the criteria are too loose.

What if a supplier refuses to share references?

Record it as a zero on that criterion and continue. Refusal is information about how the supplier will behave during the contract.