A site can have sharp copy, fair prices, and a decent brand and still sit on page four. When that happens, the fault is usually mechanical. Google can’t crawl the pages, can’t render them properly, or ranks them behind faster rivals. Fixing that plumbing is the job a technical SEO agency sells, and it is priced very differently from content or link work.
The short verdict: most UK firms with fewer than a few thousand pages should buy a one-off audit and a fix list, not a monthly retainer—budget roughly £1,000 to £5,000 for it. Sites above 10,000 pages, or any business mid-migration, get more from ongoing help at £2,000 to £5,000 a month. Freelancers cover the middle well.
Key facts at a glance
| Question | Answer |
| What the work covers | Crawling, indexing, speed, architecture, structured data, log files |
| Typical UK one-off audit | £1,000–£5,000 (deep enterprise builds up to £7,500) |
| Typical monthly retainer | £1,000–£5,000; enterprise £5,000–£20,000+ |
| Hourly consultancy rates | £70–£300, with London specialists above that |
| Time to visible results | 3–6 months for most fixes |
| Core Web Vitals pass marks | LCP 2.5s, INP 200ms, CLS 0.1 (75th percentile) |
| When crawl budget matters | Roughly 10,000+ fast-changing pages, or 1m+ pages (Google) |
Key Takeaways
- Buy the diagnosis before you buy the treatment. An audit tells you whether a retainer is worth it.
- UK prices are consistent across published guides: audits from £1,000, meaningful retainers from £1,500 a month.
- The single highest-value engagement is a site migration, and the single most expensive mistake is doing one without help.
- Most small websites need a few hours of work a year, not a twelve-month contract.
What The Work Actually Covers?
A technical SEO agency focuses on making a website legible to search engines. None of this involves writing articles or chasing backlinks. The specialist checks whether a crawler can reach a page, render it correctly, understand its structure, and decide whether it deserves a place in the index.
The scope is narrower than most sales decks suggest. In practice, a competent supplier spends their time on seven things:
- Crawling and indexing: robots.txt rules, XML sitemaps, canonical tags, noindex directives, and why pages drop out of the index.
- Site architecture: how many clicks a page sits from the homepage, and whether filtered navigation is spawning thousands of near-duplicate URLs.
- Core Web Vitals: Google’s loading and stability measures. The pass marks are 2.5 seconds for Largest Contentful Paint, 200 milliseconds for Interaction to Next Paint, and 0.1 for Cumulative Layout Shift.
- Rendering and JavaScript: whether content assembled in the browser survives the trip into Google’s index.
- Structured data: schema markup that produces review stars, prices and product availability in the results.
- Log file analysis: reading raw server logs to see which URLs bots request and which they quietly ignore.
- Migrations and redirects: the riskiest job on the list, and the one worth paying a specialist for.
Businesses with large product catalogues and frequent inventory updates often benefit more from a specialist Ecommerce SEO Agency than a general SEO provider, as they understand the technical challenges unique to ecommerce websites.
How It Differs From Content And Link Work?
| Discipline | What it fixes | Who usually does it | Typical payback |
| Technical | Crawl errors, speed, indexing, site structure | Developer-minded specialist | 1–6 months |
| On-page and content | Relevance, targeting, depth of coverage | Writers and strategists | 3–9 months |
| Off-page and links | Authority and trust signals | Outreach and PR teams | 6–12 months |
The order matters more than the budget split. Publishing more articles on a site Google struggles to crawl is like advertising a shop with the shutters down. Get the mechanics right first, then spend on words.
What A Technical SEO Agency Charges In The UK?
Published 2026 pricing from UK technical SEO agencies clusters tightly. Providers place serious retainers between £1,000 and £5,000 a month, with audits starting around £1,000 and enterprise programmes running beyond £20,000. Roughly half of UK suppliers will quote a fixed project fee instead, which suits businesses looking for a one-time technical SEO fix.
| Engagement | Typical UK price | Suits |
| One-off audit | £1,000–£5,000 | Sites under ~5,000 pages |
| Audit plus implementation | £2,000–£10,000 | Teams with no spare dev capacity |
| Retainer, smaller firm | £1,000–£3,000 a month | Ongoing publishing or a growing shop |
| Retainer, mid-market | £2,500–£5,000 a month | Competitive B2B and software |
| Migration project | £1,000–£15,000 | Replatforming or a domain change |
| Hourly consultancy | £70–£300 | Second opinions and spot checks |
Budget the developer time too. An audit is a list of tickets, and someone has to build them. If you’re getting an online shop off the ground, that implementation cost often lands with your platform partner rather than the auditor.
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Agency, Freelancer Or In-House Hire?
| Option | Cost shape | Strengths | Weaknesses |
| Specialist firm | £2,000–£5,000 a month | Bench of skills, migration experience, tooling included | Account churn; the senior name in the pitch may not do the work |
| Freelance consultant | £70–£300 an hour | Direct access to the expert, cheaper, flexible scope | Capacity limits and no cover during holidays |
| In-house hire | Salary plus 15% employer NI | Institutional knowledge, fast turnaround | Slow to recruit; one person can’t cover every skill |
Employer National Insurance sits at 15% for 2026/27, so a hire costs noticeably more than the headline figure. Before you post the role, check how candidates frame their salary expectations and compare the loaded cost against a retainer.
For a small local operator, none of the three may be needed yet. A tradesperson building up a cleaning round will get further from a Google Business Profile than from log file analysis.
Seven Questions That Separate Specialists From Generalists
Vet the practitioner, not the pitch deck. Ask these before you choose anyone, and listen for specifics rather than reassurance:
- Which crawler and log analysis tools will you use, and do we get logins?
- Can you show a redirect map from a migration you personally ran?
- Who writes the tickets our developers will pick up?
- How will you measure success beyond keyword positions?
- What happens if our dev team can’t ship your fixes?
- Which two problems would you tackle first on our site, and why?
- Will the person running the audit be on our monthly calls?
Good answers are unglamorous and precise. A reliable technical SEO agency will name the tools they use, such as Screaming Frog, explain log sample sizes, and provide clear ticket formats because they describe real processes. One that only talks about growth partnerships without showing the technical details is selling a feeling rather than a measurable service.
Red Flags Worth Watching For
- Guaranteed rankings, or a promised position for a named term.
- A quote produced without crawling your site first.
- Reports showing only rankings, never indexation or crawl statistics.
- A twelve-month lock-in with no break clause after the audit.
- Refusal to hand over the audit document or tooling if you leave.
- Fixes described but never evidenced in Search Console.
Get the deliverables written into the contract. Ask for an itemised scope the way you’d expect on any supplier agreement, and check what a compliant invoice needs to show before the first payment leaves.
For additional search marketing insights, explore our SEO category, where you’ll find in-depth guides, industry updates, and actionable optimisation tips.
What To Do Next?
Run a free crawl of your own site before you speak to anyone. Note the number of indexed pages, your Core Web Vitals status, and any redirect chains. Take that to two suppliers, ask the seven questions above, and compare their first two priorities. If both name the same problem, you’ve found your brief. If you’re formalising the business around it, our guides on setting up a limited company cover the admin side.
Once your site’s technical foundation is in place, learning what a Content Pillar Is can help you build a structured content strategy that supports higher rankings across related search topics.
Final Verdict
For most UK businesses, we’d recommend starting with a paid audit from a freelancer or a technical SEO agency, typically costing £1,000 to £3,000. Hold the retainer conversation until you’ve reviewed the findings. If you’re replatforming, changing domains, or managing more than 10,000 pages, hire a specialist technical SEO agency with proven migration case studies and accept the higher monthly investment.
Skip retainers entirely if your site is a brochure of thirty pages. Buy a few hours of consultancy a year instead. That decision alone saves the average small firm several thousand pounds.
Frequently Asked Questions
Rarely on retainer. Google’s own guidance says crawl budget management matters mainly above roughly 10,000 fast-changing pages, or a million pages overall. Below that, a clean sitemap and a periodic check of the Page Indexing report cover most of it.
Indexing corrections can move within days once Google recrawls. Speed and architecture changes usually show over three to six months, which matches the timeline UK agencies publish for campaigns generally.
Partly. Developers handle speed and server issues well. They rarely have the crawler tooling or the index diagnostics, so the usual split is a specialist writing tickets and your developer shipping them.
Both exist. Static sites need periodic checks. Sites that publish daily, run filtered product listings, or push frequent releases generate new faults constantly and justify ongoing cover.
Yes, arguably more. AI answer engines rely on crawlable, well-structured pages and clean markup to extract information. A page a botcan’tt fetch can’t be cited.
