AI for tax research: the main tools compared

The main AI tools for UK tax research fall into two groups: specialist platforms that answer from licensed tax content, such as Blue J, Croner-i and Tolley+ AI, and general assistants such as ChatGPT, Claude and Microsoft Copilot. Specialist tools cite their sources, which makes answers quicker to check. Whichever you use, the PCRT bodies’ guidance of 19 January 2026 says you stay responsible for the advice and must protect client data.

Which AI tools do UK tax advisers use for research?

UK tax practitioners mostly prefer specialist tools for client-facing research. Tolley’s 2026 tax AI report, based on a February 2026 survey of 416 UK practitioners, found 84% use AI for tax research and that “specialist tax AI platforms are the preferred choice” for high-liability work. Tolley is a vendor, so treat the figures as indicative.

The tools below are listed alphabetically. This is not a ranking.

Blue J

Blue J is a generative AI tool built for tax questions, which entered the UK through an alliance with KPMG UK. It lets you ask follow-up questions, add client context and review the sources behind each answer.

Blue J says its UK content covers legislation, HMRC publications and commentary sources, and it added curated UK case law in June 2025, from lower tribunals up to the Supreme Court. It offers a 7-day free trial with no card. Its UK pricing page, checked on 6 November 2026, showed a US dollar individual plan listing US federal coverage, so ask Blue J for a UK quote.

Croner-i

Croner-i is a UK tax and accounting information service that has added AI search to its content. In an alliance announced on 1 April 2025, KPMG UK said Croner-i would provide a “super search function, including AI functionality” giving answers with direct links to source material.

We could not open Croner-i’s own website on 6 November 2026, so we cannot confirm the current features or price of its AI tool. Ask Croner-i directly, and check whether your professional body membership includes access.

Tolley+ AI

Tolley+ AI is LexisNexis’s generative AI product for UK tax research. When LexisNexis announced it on 27 June 2024, it said the tool is “grounded in up-to-date and exclusive Tolley tax content”, with conversational search, summarising, drafting and document upload, and answers linked to sources.

On 4 February 2026 LexisNexis said its US launch “builds on the successful launch of Tolley+ with Protégé in the UK”. Prices are not published.

General AI assistants

General assistants are useful for drafting, summarising and explaining concepts, but they do not answer from a licensed tax library by default. They can mix up jurisdictions, use out-of-date rates or invent references.

Use them for low-risk tasks and check every figure against a primary source such as the HMRC manuals, last updated 6 October 2026. Our reviews of ChatGPT for accountants, Claude for accounting and Microsoft Copilot cover each one.

What do the professional rules say?

The seven PCRT bodies published guidance on using AI in tax on 19 January 2026. ICAEW’s summary sets out four main points:

• Confidentiality. Entering client data into a public AI model without consent is “likely to constitute a breach of client confidentiality”. Anonymise and genericise data.
• Verification. Check output on a risk-based approach, with professional scepticism about whether it fits the client and current law.
• Transparency. Consider how open you are with clients about AI use, and be able to explain how you reached a conclusion.
• Responsibility. You remain responsible for work produced with AI.

Which applies to you?

• If you give written tax advice to clients, use a tool that cites its sources, and check the cited source before relying on it.
• If you already subscribe to Tolley or Croner-i, ask whether AI features are included or an add-on.
• If you mainly need help drafting letters or summarising guidance, a business version of a general assistant may be enough, with client data removed.
• If you need to research a case or tribunal decision, check the tool’s case law coverage first.

How to test a tool before you buy

1. Pick five questions your firm answered recently, with known answers.
2. Ask each tool the same questions and note which sources it cites.
3. Check whether it uses 2026/27 rates and the right UK nation’s rules.
4. Read its data terms: where prompts are stored and whether they train the model.
5. Record your review in the client file, as PCRT expects you to explain your conclusion.

See the best AI tools for accountants for software beyond research.

Frequently asked questions

What is the best AI tool for UK tax research?

There is no single answer; it depends on your content subscriptions, budget and work. Blue J, Croner-i and Tolley+ AI all answer from tax-specific content and link to sources, which general chatbots do not do by default.

Can I use ChatGPT for tax research?

You can use it for drafting and explaining concepts, but check every rate and rule against HMRC or legislation. Do not enter identifiable client data without consent, under PCRT guidance of 19 January 2026.

Is it a breach of confidentiality to put client data into AI?

PCRT guidance says entering client data into a publicly available AI model without consent is likely to breach client confidentiality. Anonymise the data so the client cannot be identified.

How much does Tolley+ AI cost?

LexisNexis does not publish a price for Tolley+ AI. Contact LexisNexis for a quote, which may depend on your existing Tolley subscription.

Does Blue J cover UK tax?

Yes. Blue J says its UK content covers legislation, HMRC publications and commentary, and it added curated UK case law in June 2025.