Best LLM SEO agencies in the UK: how to choose one that actually works

TL;DR: A handful of UK agencies now offer genuine LLM SEO (getting your brand cited by ChatGPT, Gemini, Claude, and Perplexity), but most are traditional SEO shops with a new name on the tin. The best ones measure AI citation rate, answer presence, and entity authority, more than Google rankings. Expect to pay £3,000-£10,000 per month for a credible retainer.

What is LLM SEO and why do UK brands need a specialist agency?

LLM SEO is the practice of optimizing a brand's content, entity signals, and source authority so that large language models (ChatGPT, Gemini, Claude, Perplexity, and their successors) cite, recommend, or describe that brand accurately and favorably. It goes by several names: generative engine optimization (GEO), answer engine optimization (AEO), and AI visibility. The terminology is still settling.

This matters because AI assistants now handle a real and growing share of commercial queries. A 2024 study by BrightEdge found that AI Overviews appeared in roughly 84% of search queries in tested categories within weeks of Google's rollout [1]. Someone asks ChatGPT "what's the best accounting software for UK small businesses," and your brand either shows up in that answer or it doesn't. A strong Google ranking does not automatically buy you a spot in the AI answer.

The UK market has some specific wrinkles. GDPR and FCA/ICO compliance requirements affect what data you can use in content strategies. The UK's Competition and Markets Authority has been watching AI search closely since 2023 [2]. And UK audiences skew toward certain tools (Perplexity has grown fast among professionals; Microsoft Copilot is strong in enterprise thanks to the Office integration).

For more on how AI search is reshaping the visibility landscape, read that first before you evaluate any agency.

How do AI assistants decide which brands to recommend?

Most agencies can't answer this with specifics, and how they handle the question tells you a lot. AI assistants tend to cite brands that show up frequently in authoritative, structured sources: Wikipedia, high-authority news coverage, government directories, professional body listings, and clean product pages with clear entity markup.

LLMs are trained on large text corpora and then fine-tuned with human feedback. A 2024 paper by Aggarwal et al. at Georgia Tech found that pages with authoritative citations and longer-form expert content appeared in AI-generated answers at significantly higher rates, with "statistical authority" being the strongest predictor [3].

For retrieval-augmented generation (RAG) systems like Perplexity and Bing Copilot, the mechanics are closer to real-time web retrieval: they fetch and summarize pages, so traditional signals (domain authority, structured data, answer-shaped content) matter a lot. For pure LLM responses (ChatGPT without browsing), it's more about what made it into training data and fine-tuning.

The levers are practical: entity disambiguation (making sure the model knows exactly who you are and what you do), authoritative third-party mentions, structured FAQ and how-to content, and a clean knowledge graph presence. A good generative engine optimization strategy ties all of these together.

Agencies that talk only about "content velocity" or backlink counts, without addressing entity signals, are working from an outdated playbook.

What separates a real LLM SEO agency from a rebadged traditional SEO shop?

The line is blurry and moving fast. Most agencies saying "LLM SEO" or "AI SEO" today were doing traditional SEO twelve months ago. That's not automatically bad (a lot of GEO best practice overlaps with good content SEO), but it means you need to probe hard.

Here's what separates a real specialist from a shop that just updated its homepage.

They measure AI citation directly. They can show you, for a set of target queries, whether your brand appears in ChatGPT, Gemini, Claude, and Perplexity responses, how often, and in what context. If their reporting dashboard only shows Google positions and organic traffic, they're not an LLM SEO agency.

They understand entity SEO and knowledge graphs. They know what Wikidata is, how Google's Knowledge Graph relates to LLM training, and how to structure schema markup for entity clarity. Ask them to explain entity disambiguation. If they look blank, walk away.

They have a process for structured content. Answer-shaped content (FAQ schemas, HowTo schemas, clear definitions, comparison tables) is the raw material AI models extract from. Good agencies build this into briefs from the start, not as an afterthought.

They admit the limits of their own work. Nobody has reliable, peer-reviewed data on exactly how often a given content change lifts AI citation rates. Any agency claiming 100% certainty on outcomes is selling fiction. The honest ones say "we track, we test, we adjust."

They benchmark against relevant AI tools, more than Google. The AI search visibility metrics your agency tracks should include citation rate, brand sentiment in AI responses, and share of voice across at least three AI assistants.

One quick test: ask them to run a live prompt in ChatGPT for a core query in your category and talk you through it. A real practitioner will have opinions about why certain brands appear and what would need to change for yours to.

Content optimization techniques and AI visibility lift

| | | |---|---| | Statistics and data citations added | 40% | | Authoritative third-party references | 37% | | Quotable expert statements | 30% | | Fluency and readability improvements | 15% | | Keyword optimization only | 6% |

Source: Aggarwal et al., GEO paper, arXiv 2024

Which UK agencies have credible LLM SEO or AI visibility capabilities?

You'd expect a ranked list here. We're not going to give you one. The agency landscape shifts fast enough that any ranking is stale within weeks, and the right fit depends heavily on your sector, budget, and what you actually need.

Here's how to evaluate the agencies you're considering instead.

Agencies to look at seriously (based on public work and stated methodologies, as of mid-2025): Reputable UK digital agencies with documented AI visibility practices include the larger SEO consultancies (Distilled, now part of Brainlabs; Builtvisibility; and Impression) which have published substantive content on AI search. Several boutique consultancies have emerged specifically for GEO, some spun out of content strategy backgrounds. The honest caveat: we haven't independently audited any of these agencies' AI citation track records, because that data isn't publicly verifiable.

Questions to ask any agency in a pitch:

1. Can you show me the AI citation rate for a client in a category similar to mine, before and after your work?
2. What's your process for entity optimization and knowledge graph signals?
3. How do you measure success for AI visibility separately from Google rankings?
4. What tools do you use to monitor AI mentions? (Mention, Brandwatch, or specialist tools like those covered in AI SEO tools reviews.)
5. What does your content brief look like for a page targeting AI citation?

If they can answer questions 1 and 5 with specifics, they're worth a deeper conversation.

For a sense of how visibility tracking tools work in this space, the AI visibility tool overview is a useful comparison.

How much does LLM SEO cost in the UK?

Prices vary a lot and the market hasn't settled. Based on publicly available pricing signals and what agencies are quoting in the wild, here's a rough picture.

| Service tier | Monthly retainer (GBP) | What you typically get | |---|---|---| | Boutique specialist (1-5 person shop) | £2,000 to £5,000 | Entity audit, content strategy, AI citation monitoring, monthly reporting | | Mid-size agency with dedicated GEO team | £5,000 to £12,000 | Full strategy, content production, structured data implementation, multi-platform tracking | | Large integrated agency (AI SEO as part of broader SEO) | £8,000 to £25,000+ | GEO embedded in full SEO/content retainer, larger team, enterprise tooling | | One-time audit or project | £3,000 to £15,000 | Baseline AI visibility audit, entity gap analysis, recommendations |

These are indicative ranges, not guarantees. Prices run higher in London and for heavily regulated sectors (finance, legal, healthcare) where content compliance adds work.

The least useful thing you can buy right now is a basic "AI SEO package" from an agency that added AI to its keyword research tool and called it a new service. The most useful spend is a proper audit that maps your current AI citation baseline and pins down the specific gaps, before you commit to a retainer.

For context on AI SEO as a practice, read that before you evaluate costs.

What results should you realistically expect from an LLM SEO campaign?

Be skeptical of any agency promising specific citation rates on a timeline. AI citation is harder to move than Google rankings and slower to attribute. Here's the honest picture.

A well-executed GEO campaign, with entity optimization, authoritative third-party mentions, and structured content, might start showing measurable improvements in AI citation rate within three to six months for mid-competition queries. High-competition categories take longer.

A 2023 paper by Aggarwal et al. (the GEO paper) found that certain techniques, specifically statistics-rich content and authoritative citations, increased source visibility in AI-generated responses by up to 40% in controlled tests [3]. That's a controlled experiment, not a real campaign, but it gives you a sense of the magnitude on the table.

Realistic KPIs to agree with your agency upfront:

• AI citation rate for a defined set of 20 to 50 target queries (across ChatGPT, Gemini, Claude, Perplexity)
• Brand sentiment in AI responses (positive, neutral, negative)
• Share of voice versus named competitors in AI answers
• Structured data coverage and schema validation scores
• Entity accuracy on Google Knowledge Graph and Wikidata

Don't let an agency sell you on organic traffic as the primary metric for an LLM SEO campaign. Traffic is downstream of citations. Citation rate is the leading indicator you need to watch.

How do you audit your current AI visibility before hiring an agency?

Before you engage anyone, run a quick baseline audit yourself. It takes about two hours and tells you exactly where you stand.

Step one: write out 20 to 30 queries your ideal customer might ask an AI assistant. Mix informational ("what is the best way to manage cash flow for a small UK business") with recommendation queries ("recommend a payroll software for UK companies with 50 employees") and comparison queries ("compare X vs Y for [your category]").

Step two: run each query in ChatGPT (GPT-4), Google Gemini, Claude, and Perplexity. Screenshot or log the responses. Note whether your brand appears, what it says, and which competitors show up instead.

Step three: check your entity presence. Search Google for your brand name and look for a Knowledge Panel. Search Wikidata for your entity. Confirm your business information is consistent across Companies House [4], your website, Google Business Profile, and major industry directories.

Step four: run a structured data check on your top 10 pages using Google's Rich Results Test [5]. Note which pages have no schema at all.

This baseline gives you real numbers to bring into any agency conversation, and it lets you judge whether an agency's proposed work actually addresses your gaps. Spawned's AI visibility audit tool can automate much of step two at scale, which helps once you're tracking more queries than manual testing allows.

For a broader look at google AI search behavior and how it differs from third-party LLM citation, read that separately.

What does a good LLM SEO retainer actually include month to month?

Here's what a well-structured monthly engagement looks like in practice.

Month 1 (foundation): AI citation baseline audit across target queries and competitor set. Entity gap analysis. Schema audit. Knowledge graph review. Content gap mapping against queries where AI currently recommends competitors.

Month 2 onwards (execution): Typically four to eight long-form answer-optimized content pieces per month (definitive guides, comparison pages, structured Q&A pages). Entity mentions built through digital PR, press coverage, and third-party directory listings. Schema markup implementation. Wikipedia and Wikidata entity creation or correction where appropriate and accurate.

Ongoing: Monthly AI citation tracking report. Sentiment monitoring in AI responses. Competitor share-of-voice analysis. Testing new query types as the client's product or category evolves.

Good reporting looks like this: a table showing, for each tracked query, which AI tool cited your brand (yes/no), what it said, and the trend over time. That beats impressions and clicks from Google Search Console.

The agencies that do this well treat AI visibility as a distinct measurement layer alongside, not instead of, Google analytics. They're usually the same agencies that can explain the difference between RAG-based retrieval (Perplexity's approach) and pure LLM response (ChatGPT without browsing) and calibrate their tactics accordingly [6].

For a deeper look at how AI-powered search features work technically, that background helps you ask sharper questions in agency pitches.

How does Google AI Overviews change what UK agencies need to do?

Google's AI Overviews (formerly Search Generative Experience) have been live in the UK since May 2024 [7]. They pull from indexed web content using a RAG-like approach, so standard indexation and page quality still matter, but the content format needs to be answer-shaped rather than keyword-dense.

The BrightEdge data from 2024 showed AI Overviews appearing in roughly 84% of informational queries [1], though coverage has fluctuated since. Pages cited in AI Overviews tend to have clear headers, direct answers in the first paragraph, structured lists, and schema markup. Google's own guidance says the target is "helpful, reliable, people-first content" [8].

For UK brands, this means your agency needs to optimize for two somewhat different systems at once: Google's AI Overviews (which draws from your indexed pages) and the standalone AI assistants (ChatGPT, Claude, Perplexity), which draw from training data, third-party authority signals, and real-time retrieval. The tactics overlap heavily but aren't identical.

One area where UK-specific work matters: many UK business categories have strong GOV.UK and NHS content dominating AI Overviews for informational queries. A good agency knows how to position client content as a complementary authoritative source rather than trying to displace government content directly. That's a judgment call that needs UK market knowledge.

Red flags to watch for when evaluating LLM SEO agencies

A few things that should make you walk away.

Guaranteed ranking positions in AI tools. No agency can guarantee ChatGPT will recommend you. The models change, fine-tuning updates happen, and retrieval systems shift. Anyone promising specific citation rates is lying.

AI SEO delivered entirely through content volume. Publishing 50 blog posts a month is not GEO. Quantity without entity authority and structural quality does very little for AI citation rates.

No mention of third-party authority signals. Digital PR, Wikipedia entity presence, industry body listings, and authoritative backlinks matter for AI training data. An agency focused only on on-site content is missing half the picture.

Reporting that only shows Google metrics. If after three months your only evidence of progress is Google position improvements and organic traffic, you hired a traditional SEO agency with a new label.

No transparency about measurement methodology. Ask how they run queries to measure AI citation. Do they use the same prompt phrasing every time? Do they test in incognito/logged-out sessions? Do they track across multiple AI tools? If they haven't thought about prompt consistency, their data is noisy.

Aggressive upsells on proprietary AI-detection tools. Several agencies sell expensive "AI monitoring" software that's essentially a thin wrapper around API calls to GPT-4. The underlying tools (Semrush, Ahrefs, Brandwatch, dedicated GEO trackers) are available directly. Don't pay a 300% markup for a rebadged dashboard.

For reference on what good AI visibility measurement looks like from the tool side, the brandrank.ai visibility insights analysis is a useful comparison point.

Should you hire an LLM SEO agency or build this capability in-house?

For most UK brands, the right answer right now is a hybrid. The field is new enough that even the best external agencies are learning in real time. The risk of pure agency dependence is that your internal team never builds the judgment to evaluate what they're being sold.

A practical path for a brand with a proper marketing function: hire an agency for six to twelve months to do the foundational work (entity cleanup, structured content templates, citation baseline measurement), while embedding a content or SEO person on your side who attends every strategy meeting and learns the methodology. After twelve months, you can often move much of the ongoing content work in-house, keeping the agency for measurement, PR strategy, and staying current with how the AI tools change.

For a startup or a brand with a small marketing team, a retainer with a specialist agency makes more sense, because doing this properly in-house eats more time than a lean team has.

The AI mode SEO tool landscape is worth tracking if you want to build partial in-house capability without recreating everything from scratch.

At Spawned, we see brands get the best outcomes when the agency handles strategy and authority-building while the brand's own team owns content production. The split keeps costs manageable and keeps institutional knowledge inside the company.

Sources

1. BrightEdge, AI Overviews Research, 2024
2. UK Competition and Markets Authority, AI Foundation Models Update, 2024
3. Aggarwal et al., Generative Engine Optimization (GEO), arXiv 2024
4. Companies House, UK Government business registry
5. Google, Rich Results Test tool
6. Perplexity AI, About page and technical documentation
7. Google, AI Overviews UK rollout announcement, 2024
8. Google Search Central, Helpful content guidelines
9. UK Information Commissioner's Office, Guidance on AI and data protection
10. Financial Conduct Authority, Financial promotion rules