Compare · ChatGPT
Using ChatGPT for tax research? Nylon vs ChatGPT for UK accountants
ChatGPT is OpenAI’s general AI assistant, with web search, file uploads, deep research and a free plan. If you use it for tax research, compare where its answers come from, how you check them, what happens to your clients’ data and what you pay. Here’s how Nylon compares, how to use the two together, and when ChatGPT is still the better fit.
Nylon vs ChatGPT: the short answer
As at 24 October 2026. Nylon’s prices are in pounds sterling. ChatGPT’s are OpenAI’s US list prices before tax; OpenAI says it offers localised pricing, so you may see pounds. Details and sources below.
ChatGPT
Nylon
Answers from
Its training, plus the web when search runs
UK tax legislation, HMRC manuals and guidance, and tax decisions
Citations
With search, may be included; OpenAI says they can be incomplete, outdated or incorrect
Every answer cites and links the primary source
Model training
Free, Go, Plus, Pro: on unless you opt out. Business, Enterprise: off by default
Your inputs are never used, on any plan
Price before tax
Free plan; Plus US$20 a month; Business Standard US$20–$25 per user a month
£39–£199 per user a month, ex VAT
Breadth
Any topic, with deep research, file uploads and apps
UK tax, with drafting and document review
Choose Nylon for UK tax answers cited to legislation, HMRC guidance and tax decisions. Choose ChatGPT if you mainly want a general assistant for drafting and everyday work. Or use both: with an Adviser or Elite seat, Nylon’s connector brings its research into ChatGPT, where your ChatGPT plan allows it.
Each vendor’s own website is the source for its column.
ChatGPT alternatives for tax research at a glance
What each product says about itself on its own website, as at 24 October 2026. Prices exclude VAT unless stated.
Nylon
Cited AI answers from UK primary sources, in Nylon or your AI assistant
Yes, on every plan
£39, £99 or £199 per user a month
Tolley
Simon’s, De Voil and Tolley guidance, with AI built in
Yes, in Tolley+ with Protégé
Quote-based
Croner-i
Croner commentary and guidance, with a tax and VAT advice line
Yes, from Croner’s content and your uploads
Quote-based
Blue J
AI research across UK, US and Canadian tax (jurisdictions depend on your subscription)
Yes
£1,500 a year per user (sole practitioners; VAT not stated); teams: quote
Accordance
Multi-agent AI for tax, audit and accounting teams
Yes, with a source list
Not published
Claude, Gemini or Copilot on their own
Quick drafting where nobody needs to trace the source
When they search the web
Free and paid plans
Why choose Nylon over ChatGPT for UK tax research
As at 24 October 2026. ChatGPT is quick, broad and good at drafting. Nylon is built for UK tax answers you can trace to the source, and it works inside ChatGPT too.
Answers from UK tax law
Nylon answers from UK tax legislation, HMRC manuals and guidance, and tax decisions from the tribunals and courts, and links each citation to the source. ChatGPT answers from its training and, when search runs, the web. OpenAI’s help centre says search results and citations “can be incomplete, outdated, or incorrect”.
Accredited and benchmarked
Nylon is accredited under the ICAEW Technical Accreditation Scheme, after an independent technical evaluation by RSM UK. In Nylon’s October 2026 benchmark of 91 Australian (not UK) tax questions, Nylon scored 4.68 out of 5 and OpenAI’s GPT-6 Astra 4.28. GPT-6 Astra ran through OpenAI’s API, not the ChatGPT app, and was limited to 20 tool calls per question; the Claude and Gemini models had no limit.
Never used for training
Nylon never uses your inputs to train AI models, on any plan. On ChatGPT’s Free, Go, Plus and Pro plans, OpenAI may use your chats to train its models unless you turn off “Improve the model for everyone”. Business and Enterprise workspaces aren’t used for training by default.
Keep ChatGPT, add Nylon
Adviser and Elite seats include Nylon’s AI connector for ChatGPT, so ChatGPT can search Nylon’s library and cite the source. Your ChatGPT plan and workspace settings decide whether you can add it.
1. Nylon
Nylon: cited AI answers from UK primary sources
Nylon answers UK tax questions from tax legislation, HMRC manuals and guidance, and tribunal and court decisions, and links every citation to the source.
Cited answers
Every answer comes with hyperlinked citations to the primary source.
UK tax library
UK tax legislation, HMRC manuals and guidance, and tax decisions from the tribunals and courts.
Drafting and review
Draft advice letters, research memos and tax opinions, or upload client documents and ask what matters.
In your AI tools
Adviser and Elite seats include Nylon’s AI connector for Claude, ChatGPT and Microsoft Copilot.
Pricing
Starter £39, Adviser £99 and Elite £199 per user per month, ex VAT. Billed monthly; cancel anytime. Enterprise pricing on request.
Nylon
When does a business have to register for VAT?
You must register if your taxable turnover for the last 12 months has gone over £90,000, or you expect it to go over £90,000 in the next 30 days alone [1]. Under the 12-month test, tell HMRC within 30 days of the end of the month you went over [2].
1
Value Added Tax Act 1994, Sch 1 para 1
2
Value Added Tax Act 1994, Sch 1 para 5
Illustrative example
Benchmark · October 2026
4.68 / 5
Nylon’s composite score on 91 CPA Program Australia Taxation questions, each graded by an AI judge against an expert reference answer, without being told which system wrote it.
Nylon
4.68
Claude Fable 5.1
4.32
GPT-6 Astra
4.28
Australian tax, compared with five general AI models run through their providers’ APIs from 28 September to 1 October 2026. OpenAI’s two models were limited to 20 tool calls per question; Claude and Gemini had no limit. The ChatGPT app and specialist tools weren’t tested.
Nylon vs ChatGPT, side by side
As at 24 October 2026. The ChatGPT column comes from OpenAI’s website and help centre.
Where you use it
ChatGPT, with apps for services such as Google Drive, Slack and SharePoint. Apps that connect to internal tools need Plus or above.
Nylon on the web, and Claude, ChatGPT and Microsoft Copilot through the AI connector (Adviser and Elite).
Contract
Plus and Pro: monthly, renewing automatically; cancel anytime. Business: monthly or annual, minimum 2 seats; annual seats stay committed for the term.
Monthly. Cancel anytime.
Price (before tax)
Free plan. Plus US$20 a month; Pro from US$100 a month. Business Standard US$25 per user a month, or US$20 billed annually. Enterprise: contact sales. US prices; OpenAI says prices may vary by country.
£39, £99 or £199 per user a month, ex VAT. Enterprise: quote.
What answers draw on
The model’s training, the web when search runs, and your uploaded files and connected apps. A curated UK tax library isn’t described on OpenAI’s public pages.
Nylon’s library: UK tax legislation, HMRC manuals and guidance, and tax decisions from the tribunals and courts.
Citations
Answers that use web search “may include citations”, which OpenAI says “can be incomplete, outdated, or incorrect”. Deep research reports include citations or source links.
Every answer links each citation to the primary source.
Model training
Free, Go, Plus and Pro: OpenAI may train on your chats unless you opt out in Data controls. Business, Enterprise and Edu: not used for training by default.
Your inputs are never used to train AI models, on any plan.
Jurisdictions
Any topic and any country, from the model’s training and the web.
UK, Australian and New Zealand tax legislation and guidance in one library.
Tools
Deep research, projects, document uploads up to 512 MB a file, and apps.
Deep research on Adviser and Elite. Drafts advice letters, research memos and tax opinions, and reviews uploaded client documents.
Security
Business: SOC 2 Type 2. Enterprise and Edu: also ISO/IEC 27001 and 27701. OpenAI also lists ISO/IEC 42001 for its AI management system.
SOC 2 Type 1, SOC 2 Type 2, ISO 27001, ISO 42001
Try before you buy
Free plan.
Book a demo to test Nylon on your own questions.
What you gain with Nylon
Answers cited to UK tax legislation, HMRC guidance and tax decisions
Inputs never used to train AI models, on every plan
UK, Australian and New Zealand tax legislation and guidance in one library
Nylon inside ChatGPT, Claude and Microsoft Copilot (Adviser and Elite)
What you give up
ChatGPT’s free plan, and Plus at US$20 a month
A general assistant for writing and tasks on any topic
ChatGPT’s apps for services such as Google Drive, Slack and SharePoint
Test Nylon on your own ChatGPT questions
Bring three tax questions you asked ChatGPT this month. In the demo, we’ll run them in Nylon so you can check each answer against its sources.
Other ChatGPT alternatives for tax research
Each summary comes from the product’s own website, as at 24 October 2026.
2
Tolley
LexisNexis’s UK tax brand. Tolley+ with Protégé, renamed from Tolley+ AI in 2026, gives AI answers that link to Tolley research and guidance, including Simon’s Taxes, De Voil, and current and historic HMRC manuals.
Best for
Tax teams that want Tolley commentary and guidance, with AI from the same publisher.
Pricing
Quote-based. 7-day free trial of Tolley+ Guidance for individuals based in the UK and Ireland.
Consider it if
You want expert commentary and practical guidance alongside AI answers.
3
Croner-i
Croner’s tax, audit and accounting information service: commentary, legislation, tax cases, HMRC manuals and a tax and VAT advice line. Its AI assistant, Croner Intelligence, answers from Croner’s own expert content, plus any documents you upload.
Best for
Practices that want Croner commentary and guidance, with an expert advice line.
Pricing
Quote-based, ex VAT. A fixed first term that renews unless you give written notice at least 90 days before it ends.
Consider it if
You want a telephone advice line alongside your research tool.
4
Blue J
AI tax research with in-line citations. Its UK answers draw on legislation, HMRC manuals and guidance, VAT notices, and tax tribunal and court decisions, plus Tax Notes commentary and IBFD content. It also has US and Canadian editions.
Best for
Firms that want AI tax research backed by Tax Notes and IBFD content.
Pricing
£1,500 a year per user for sole practitioners (VAT not stated); teams by quote. Annual plans. 7-day free trial.
Consider it if
You also research US or Canadian tax.
5
Accordance
A San Francisco multi-agent AI platform for tax, audit and accounting teams. It shows its reasoning and a source list. Its public pages describe US federal, state and international tax.
Best for
Firms that want one AI across tax, audit and accounting work.
Pricing
Not published; book a demo. One-year term by default, renewing automatically.
Consider it if
Your work is mainly US tax. UK tax coverage isn’t described on Accordance’s public pages.
6
Claude, Gemini or Copilot on their own
General AI assistants from Anthropic, Google and Microsoft. Like ChatGPT, they answer from their training and, when they use it, web search.
Best for
Quick drafting and orientation where nobody needs to trace the answer.
Pricing
Free and paid plans.
Consider it if
You add Nylon’s AI connector to Claude or Copilot (Adviser and Elite), so they search Nylon’s library and cite the source.
Which should you choose?
As at 24 October 2026. Match the tool to the work you do most.
If you want cited answers on UK tax
Nylon
In Nylon, or in ChatGPT, Claude and Copilot with an Adviser or Elite seat. Billed monthly.
If you want to keep working in ChatGPT
Use both: Nylon inside ChatGPT
With an Adviser or Elite seat, add Nylon’s connector where your ChatGPT plan and workspace settings allow it. ChatGPT then searches Nylon’s library and cites the source.
If you mainly draft, summarise and brainstorm
ChatGPT
A general assistant for any topic, with a free plan.
If your work runs on publisher guidance
Tolley or Croner-i
Simon’s, De Voil, Croner commentary and an advice line.
If you also research US or Canadian tax
Blue J
UK, US and Canadian tax in one tool, if your subscription covers them.
If you want AI across tax, audit and accounting
Accordance
Multi-agent AI with visible reasoning and a source list.
Security your firm can check
Nylon is SOC 2 Type I and Type II audited, and ISO 27001 and ISO 42001 certified.
Independently audited
SOC 2 Type I and Type II reports are available, and Nylon holds ISO 27001 and ISO 42001 certification.
Encrypted
All data that passes through Nylon is encrypted in transit and at rest.
Not used for training
Your inputs are never used to train AI models.
Admin controls
Every plan includes advanced organisational controls.
Baqir Hussein, FCCA · Founder & Director, Finex Chartered Certified Accountants
Nylon vs ChatGPT: frequently asked questions
Questions about using Nylon with ChatGPT? Book a demo or email support@usenylon.com.
Can I use ChatGPT for tax research?
Yes, for orientation and first drafts, if you check what it tells you and protect client confidentiality. As at 24 October 2026, OpenAI’s terms for UK users say you shouldn’t rely on its output “as a sole source of truth or factual information, or as a substitute for professional advice”. Whichever AI tool you use, Nylon included, the professional bodies’ PCRT guidance on AI (January 2026) says to treat its output “as if it were prepared by a less experienced junior colleague and reviewed with appropriate scepticism”. Nylon links every answer to the legislation, HMRC guidance or decision it relies on, so you can check it against the source.
Is ChatGPT accurate for tax questions?
OpenAI says ChatGPT “can make mistakes”, and no AI tool is error-free, Nylon included. Nylon’s October 2026 benchmark tested Australian tax, not UK tax: on 91 CPA Program Australia Taxation questions, run from 28 September to 1 October 2026, OpenAI’s GPT-6 Astra scored 4.28 out of 5 and GPT-6 Sol 3.96, against 4.68 for Nylon. Both ran through OpenAI’s API, not the ChatGPT app, with the benchmark’s shared web-search tool and no system prompt. They were limited to 20 tool calls per question, unlike the Claude and Gemini models; GPT-6 Sol hit that limit on 52 of the 91 questions and GPT-6 Astra on 7, so their scores may understate them, and ChatGPT’s results may differ. As at 24 October 2026, OpenAI says GPT-6, powered by GPT-6 Sol, is rolling out as the default in ChatGPT’s Chat for eligible Plus, Pro, Business and Enterprise users.
What is the best alternative to ChatGPT for tax research?
If you want cited answers on UK tax, Nylon: it links every answer to the primary source, is accredited under the ICAEW Technical Accreditation Scheme, never uses your inputs to train AI models, and works inside ChatGPT with an Adviser or Elite seat, where your ChatGPT plan allows it. If your work runs on commentary and practical guidance, Tolley or Croner-i. For UK, US and Canadian tax in one tool, if your subscription covers them, Blue J. For AI across tax, audit and accounting, Accordance.
Does ChatGPT use my clients’ data to train its models?
It depends on the plan. As at 24 October 2026, OpenAI says it may use content from its individual plans (Free, Go, Plus and Pro) to train its models, unless you turn off “Improve the model for everyone” in Data controls or use a Temporary Chat. It doesn’t train on Business, Enterprise or Edu workspace content by default. Nylon never uses your inputs to train AI models, on any plan.
How does ChatGPT pricing compare with Nylon?
As at 24 October 2026, OpenAI lists ChatGPT Plus at US$20 a month and Pro from US$100 a month. ChatGPT Business Standard seats cost US$25 per user a month, or US$20 billed annually, with a 2-seat minimum. These are US prices before tax, and OpenAI says prices may vary by country. There’s also a free plan. Nylon costs £39, £99 or £199 per user a month ex VAT, billed monthly. If you keep ChatGPT and add Nylon, you pay for both.
Can I try Nylon before I buy?
Book a demo to see Nylon answer your own questions. Plans are monthly and you can cancel anytime. ChatGPT has a free plan.
Can I use Nylon in ChatGPT, Claude or Copilot?
Yes, with an Adviser or Elite seat, if your assistant’s plan and workspace settings allow connectors. Nylon’s AI connector lets those assistants search Nylon’s library and cite the source.
Is Nylon secure enough for client work?
Nylon is SOC 2 Type I and Type II audited, and ISO 27001 and ISO 42001 certified. Data is encrypted in transit and at rest, and your inputs are never used to train AI models.
Keep exploring
Nylon for accountants
Research, drafting and review for accounting firms.
Tax research benchmark
91 Australian tax questions, six systems, graded against expert answers.
Nylon for ChatGPT
Cited Nylon research inside ChatGPT.
Plans
Starter, Adviser and Elite, billed monthly.
Apart from Nylon’s own benchmark, information about ChatGPT and the other products comes from their own websites as at 24 October 2026 and can change. Prices are in pounds sterling unless marked US$. ChatGPT, GPT and OpenAI are trade marks of OpenAI, and other product names belong to their owners. Nylon isn’t affiliated with or endorsed by OpenAI or any of those owners. Nylon’s October 2026 benchmark tested Australian tax. It ran OpenAI’s GPT-6 Astra and GPT-6 Sol through OpenAI’s API, not the ChatGPT app, with a limit of 20 tool calls per question that the Claude and Gemini models didn’t have, and didn’t test the other products on this page. Spotted something out of date? Email support@usenylon.com.