Twenty practical technical SEO checks for a UK service business, ordered by impact. This is the same shortlist used to triage a new client's site in the first week of an engagement. It is the layer underneath all the content work.
Crawlability and indexing
Can Google actually find your pages? If the answer is no, nothing else matters.
| Check | Why it matters | Passing signal | Fail signal |
|---|---|---|---|
| HTTPS sitewide | Prerequisite for indexing and trust | Every URL loads over https | Mixed content warnings |
| XML sitemap | Tells Google what to crawl | Submitted in GSC, all pages listed, no errors | Missing, outdated, or contains excluded pages |
| Core Web Vitals | Speed and stability ranking factor | All three green (LCP under 2.5s) | Yellow or red on mobile |
| Schema markup | Enables rich results and AI citation | Organization, Service, FAQPage validated | No schema or errors in Rich Results Test |
| Internal linking | Signals importance and crawl paths | Every page 3 clicks or fewer from home | Orphaned pages |
- Your site is indexed in Google. Search site:yourdomain.co.uk. Your pages should appear. Common causes of blocking: a wrongly-flipped discourage search engines setting, a stray robots.txt block, or a noindex tag left on after launch.
- You have an XML sitemap submitted to Search Console. Check it lists all important pages and no junk (filter pages, tag archives, admin URLs).
- Your robots.txt does not block important pages. Visit yourdomain.co.uk/robots.txt. Look for Disallow lines pointing at directories you want indexed.
- No important pages have a noindex tag. Spot-check half a dozen pages by viewing source and searching for noindex.
- Internal links resolve. No 404s in your menus, footers or main page links.
Site speed and Core Web Vitals
Google's quality signals weight loading speed, particularly on mobile. AI engines too: a page that takes seven seconds to load is less likely to be cited than one that takes two.
- Your homepage loads in under three seconds on mobile. Test in PageSpeed Insights. Anything over four seconds needs work.
- Your Largest Contentful Paint (LCP) is under 2.5 seconds. Slow images, oversized JavaScript and bloated themes are the usual culprits.
- Your Cumulative Layout Shift (CLS) is under 0.1. Ads, late-loading fonts and missing image dimensions cause this.
- Your Interaction to Next Paint (INP) is under 200 milliseconds. Heavy third-party scripts and badly-written JavaScript are the usual problem.
Mobile and accessibility
Over sixty percent of UK searches happen on mobile. Your mobile site is the default that Google indexes.
- Mobile rendering is clean. Text readable without pinching, buttons large enough to tap, no horizontal scrolling, no pop-ups blocking content.
- Tap targets are at least 48 pixels.
- All images have meaningful alt text. Not image001.jpg. A short, descriptive sentence.
Structured data and on-page foundations
- Organisation schema on the homepage. Business name, logo, address, phone, social profiles. Test in Google's Rich Results Test.
- Article schema on every blog post. Author, publish date, headline, featured image. Most SEO plugins handle this automatically when configured.
- FAQ schema where you have FAQ blocks. Helps AI engines extract clean answers. Do not abuse this.
- Local Business schema on your contact and service pages. Especially important if you serve a specific geographic area.
- Each page has a unique H1. One H1 per page, matching the topic.
- Meta titles are 50 to 60 characters. Anything longer gets truncated.
- Meta descriptions are 150 to 160 characters. They should actually persuade someone to click.
Site health
- HTTPS is on, and there are no mixed-content warnings. Mixed content (HTTPS page loading HTTP images) used to be common after a half-finished migration.
How to use this checklist
Do not try to fix everything in a week. Score the list, then sequence the fixes by impact. Crawlability and indexing first, then speed, then schema, then the smaller polish items. For a UK service business, the realistic timeline is four to eight weeks to clean a site to a strong baseline, working with a developer or capable in-house team. Most of these items take less than an hour each.
How often should I run a technical SEO check?
A quick spot-check quarterly, a deep audit annually, and an extra check after any significant change to the site (redesign, plugin swap, template update, migration). Most issues creep in after changes, not from organic drift.
Do I need a developer to fix these issues?
For about half of the list, no. Title tags, meta descriptions, alt text, sitemap submission, schema via a plugin: these are content-team tasks. For Core Web Vitals, server-level performance and structural changes, you usually need a developer.
Will fixing technical SEO instantly improve my rankings?
Sometimes, often no. Technical SEO is a foundation; it removes obstacles rather than adds boosts. The lift shows up in the months that follow as your content work compounds on top of a healthy site. Without the foundation, the content work stays under-rewarded.
What is the most commonly missed item?
FAQ schema where the content is actually structured as FAQs but the schema markup never got added. It is a five-minute fix that consistently improves citation rates in AI Overviews.
How does this list relate to AI Overviews?
Every item on the list contributes. Fast, well-structured pages with clean schema get cited disproportionately by AI engines. A site that fails the technical checklist will struggle to be cited even with great content.