How to get your plumbing business recommended by AI

To get a plumbing business recommended by AI, you need to be in two places: your Google listing and website, which is where ChatGPT looks, and the trade directories that Claude and Gemini read. Those directories are TrustATrader, MyBuilder, Checkatrade, HaMuch and Three Best Rated. When we asked all three assistants for a plumber in 5 UK towns, they read almost completely different sources.

Here's what they did, town by town, and what I'd change if I were the plumber.

What we tested

On 2 October 2026 WhereInAI asked ChatGPT, Claude and Gemini the 3 questions our scan generates for a plumber, in 5 towns: Bath, Leeds, Norwich, Swindon and Exeter.

• best plumber in [town], UK
• recommend a good plumber in [town], UK
• who is the top rated plumber in [town], UK

That's 45 answers, 15 from each assistant, all with web search switched on. We added "UK" because without it, Gemini answered "best plumber in Bath" with plumbers in Bath, Maine. Every answer is stored, so these figures can be rechecked.

One honest limit up front. We used the versions of each assistant that developers get (GPT-4.1 mini, Claude Haiku 4.5 and Gemini 2.5 Flash-Lite, each with its own web search). The ChatGPT app on your customer's phone runs a bigger model and knows roughly where they are. The pattern below is what WhereInAI measures; the app's exact list will differ.

Where each assistant looked

That table is the whole story in miniature. ChatGPT went straight to plumbers' websites and Google. Claude and Gemini went to directories and lifted names off them.

ChatGPT reads your Google listing and your website

In 14 of its 15 answers ChatGPT printed a small card for each plumber, like this one from Bath:

Closed · Plumber · 5.0 (15 reviews)
21 Woodhouse Rd, Bath BA2 1ST, United Kingdom

That's the shape of a Google Business Profile: category, rating, review count, address, opening status. It never linked a single trade directory.

So for ChatGPT, the two things you control directly are the ones that count. I've gone into the Google side in Does your Google Business Profile affect ChatGPT?, and into how ChatGPT builds its list in How ChatGPT decides which local businesses to recommend.

Claude and Gemini read the trade directories

These directories were cited in every one of the 5 towns:

Claude also cited Yelp (10 links), PlumbersUp (8) and MyJobQuote (6), and Gemini cited Which? Trusted Traders twice.

The links went to the directory's town page, like trustatrader.com/plumbers-in-bath-and-north-east-somerset or mybuilder.com/plumbing/plumber-tradespeople/bath. So the plumbers Claude and Gemini named were, in large part, the plumbers at the top of those pages.

Three Best Rated deserves a note. It names 3 plumbers per town and says it picks them with a 50-point inspection, so you can't simply sign up. Both Claude and Gemini cited it in all 5 towns.

Claude sometimes won't answer

Claude refused 4 of the 5 "recommend a good plumber" questions. It didn't search. It said it had no access to listings and suggested the customer check Google and Checkatrade themselves. The same Claude, asked "best plumber" or "who is the top rated plumber", searched and named firms.

I can't tell you why that wording trips it. I can tell you that the customer who types it gets no names at all, which is worth knowing before you read too much into any single test.

The three assistants rarely agree

Across the 5 towns, the assistants linked to 56 plumbers' own websites between them.

• 48 were linked by only one assistant.
• 1 was linked by all three: Royal Flush Plumbing in Norwich.

So "ChatGPT recommends us" says almost nothing about Claude or Gemini. They are reading different parts of the web.

What I'd do as a plumber

This is inference from one day of answers in 5 towns, so treat it as a sensible order of work. Nothing here comes with a promise.

1. Get your Google Business Profile complete and accurate. Category, service area, hours, phone, website link, and real reviews. That's the card ChatGPT printed in 14 of 15 answers.
2. Make your website say what you do and where, in plain words. "Plumbing and heating in Swindon and Highworth, Gas Safe registered" near the top of the page. ChatGPT linked plumbers' own sites 59 times.
3. Don't block the AI crawlers. ChatGPT's search crawler is called OAI-SearchBot. If your robots.txt or hosting firewall blocks it, ChatGPT can't read your site.
4. Be on the directories Claude and Gemini read. TrustATrader, MyBuilder, Checkatrade and HaMuch came up in every town. Check what each one costs before you join, and keep your name, address and phone identical on all of them.
5. Ask happy customers to review you on the directory you've joined. The top of a directory's town page is what got named, and reviews are what move you up it.

If you want the general directories as well, TownDirectory gives you a free UK listing, and CitationHQ will submit you to the main UK directories for you. Both are run by the same company as WhereInAI.

The limits of this

One day, 5 towns, one answer per question. Assistants change how they answer without notice, and the consumer apps run different models from the ones tested here. Plumbers in other towns will see different names, though I'd expect the same sources, since those directories turned up in every town we tried.

To see who each assistant names for your own business and town, run a free scan. We ran the same test for dentists and garages, and the sources were different for each trade. If you're wondering why a rival keeps getting named and you don't, Why AI recommends your competitors and not you goes through it.