Technical SEO advertising rules explained for England

What to take away

Technical SEO advertising rules are the advertising, consumer protection, data protection and platform standards that apply when you audit, promote or report on websites in England.

Three sources set the baseline: the CAP Code, enforced by the Advertising Standards Authority (ASA); UK data protection and privacy law — UK GDPR, the Data Protection Act 2018 and PECR — supervised by the Information Commissioner's Office (ICO); and Google's crawling documentation.

Claims and advertising standards in England

The UK Code of Non-broadcast Advertising and Direct & Promotional Marketing — the CAP Code — is written by the Committee of Advertising Practice (CAP) and enforced by the Advertising Standards Authority (ASA). It applies across the UK, including England, and covers paid search copy, landing pages, case studies, pricing claims and other marketing communications that reach consumers.

The codes set the baseline for accuracy, substantiation, social responsibility and comparative advertising. Section 3 of the CAP Code, on misleading advertising, is where most technical SEO claims sit. Rule 3.1 says marketing communications must not materially mislead or be likely to do so, and rule 3.11 says they must not mislead consumers by exaggerating the capability or performance of a product. Rule 3.9 adds that they must not mislead by omitting significant limitations and qualifications, which is where a speed or ranking claim without its test conditions goes wrong.

An audit report is not itself an advert, but claims drawn from it often are. A landing page stating that a site loads faster needs evidence before it goes live.

Substantiation and evidence files

Rule 3.7 of the CAP Code requires marketers, before publication, to hold documentary evidence to prove claims that consumers are likely to regard as objective and that are capable of objective substantiation. The ASA may regard claims as misleading in the absence of adequate substantiation. Keep the crawl date, tool version, sample size and raw export together. If a claim is challenged, you can show what was measured and when.

A screenshot of a dashboard is weak evidence on its own. Keep the export file, the tool settings and the name of the person who ran the check.

Comparative claims and benchmarks

Comparative claims, such as being faster than a named competitor, face a higher standard. The ASA treats unqualified superlative claims as comparative claims against all competing products, and superiority claims must be supported by evidence unless they are obvious puffery. Under rules 3.32 to 3.34, a comparison with an identifiable competitor must not mislead, must compare products meeting the same needs, and must objectively compare material, relevant, verifiable and representative features. Benchmarks must be like-for-like and current, so state which dataset produced any sector median and when. Our guide to Technical SEO data protection in England covers the personal data inside those benchmarks.

Reviews, testimonials and guarantees

Agency marketing leans on client quotes and promises, and Section 3 covers both. Rule 3.44 bans fake consumer reviews, rule 3.45 requires incentivised reviews to be made clear, and rule 3.47 requires marketers to hold documentary evidence that a testimonial is genuine, with contact details for the person or organisation that gave it. Rule 3.55 says the word "guarantee" must not be used in a way that could cause confusion about a consumer's rights, a point worth checking before any proposal promises rankings.

Consumer protection law and who enforces it in England

Two statutes sit alongside the CAP Code. The law on unfair business-to-consumer trading is now in the Digital Markets, Competition and Consumers Act 2024, and the Competition and Markets Authority published its guidance on the conduct that law prohibits (CMA207) in April 2025; the ASA takes the unfair commercial practices provisions in Chapter 1 of Part 4 of the Act into account when it rules on complaints about misleading marketing. The Business Protection from Misleading Marketing Regulations 2008 cover advertising addressed to businesses. Both catch the kind of promise a technical SEO proposal tends to make — guaranteed page-one rankings, for instance — and local authority Trading Standards services and the Competition and Markets Authority enforce them in England.

Data, crawling and reporting duties

Two further rule sets shape daily technical SEO work: data protection law and the conventions governing automated access.

Personal data in analytics and audits

Analytics, log files and reporting dashboards often hold personal data, so UK GDPR and the Data Protection Act 2018 apply, with the ICO as the UK supervisory authority. The ICO's data protection principles guidance explains the principles underpinning lawful processing, including purpose limitation and storage limits. In an audit, collect the minimum data needed and keep identifiable user data out of client reports.

Retention matters as much as collection. Decide how long raw logs and exported reports are kept, then delete them on schedule instead of leaving old exports on shared drives.

This is general guidance only. Individual cases need a qualified adviser, particularly where special category data is involved.

Cookies, tracking and consent

PECR sits alongside UK GDPR and covers storage and access technologies, so analytics and advertising cookies that are not strictly necessary need consent before they run. The ICO's cookies guidance and its direct marketing guidance set out how to word that consent and how to keep the record of it. When you audit a site, check whether tags fire before consent and whether consent records are kept.

Robots.txt and automated crawling

The robots.txt file is the standard way to tell crawlers what they may request. Google's documentation on how Google interprets the robots.txt specification is the reference to follow when you configure or test crawl rules. An audit tool that ignores robots.txt risks breaching site terms and producing findings that do not match real search behaviour.

Check the live file before a large crawl, because staging and production rules often differ. A directive that blocks a path also stops an audit tool from seeing it.

A working checklist for English teams

The table compares the three rule sources that most often affect technical SEO advertising and reporting.

Who signs off each claim

Give every public claim a named owner and a review date. In a small team, one person may wear two hats, which is fine while the record exists. A complaint should be answerable within days.

Keep the approval note short: the claim, the evidence, the date and the approver's name. That note is what you hand over if the ASA asks questions.

What to do when rules change

Regulator guidance and platform documentation are updated periodically. Put a quarterly review in the calendar and re-test any automated check that depends on them. If a change affects live client work, tell the client early.

Common questions

Do ASA rules apply to a technical SEO audit report?

Only where the report, or claims drawn from it, becomes a marketing communication reaching consumers. Audit notes are not adverts, but a public case study repeating a performance claim is covered.

Can I publish client performance data in a case study?

You need a lawful basis for any personal data and permission for commercially sensitive detail. Aggregate figures where possible and avoid identifiable user-level data.

Is ignoring robots.txt a legal problem in England?

It can breach a site's terms of use and, in some circumstances, computer misuse law. It also undermines audit accuracy, because Google's crawling follows the specification.