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Nylon for ChatGPT
Cited UK tax research in ChatGPT
Nylon for ChatGPT brings Nylon’s UK tax library into ChatGPT: tax legislation, HMRC manuals and guidance, and tax tribunal and court decisions. ChatGPT searches the sources, reads the documents and links every citation, so you can check the answer. Install it from ChatGPT’s plugin directory with a Nylon Adviser or Elite seat.
Read-only access
Your own Nylon sign-in
SOC 2 Type 2
ISO 27001
ChatGPT
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Using Nylon, when is a gift to an employee a tax-free trivial benefit?
Searched Nylon’s UK tax library
Read 2 documents
A benefit is tax-free if it isn’t cash or a cash voucher, costs £50 or less, isn’t provided under salary sacrifice or a contractual obligation, and isn’t a reward for particular work the employee has done [1]. For a director of a close company, the exemption is capped at £300 a tax year [2].
1
Income Tax (Earnings and Pensions) Act 2003, s 323A
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2
Income Tax (Earnings and Pensions) Act 2003, s 323B
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Illustrative example
Nylon for ChatGPT at a glance
What it is
A read-only plugin that adds Nylon’s search and documents to ChatGPT, built on the Model Context Protocol (MCP).
What ChatGPT can read
UK tax legislation, HMRC manuals and guidance, and tax decisions from the tribunals and courts.
Who can use it
Anyone with a Nylon Adviser or Elite seat whose ChatGPT plan and workspace allow plugins.
Where it works
ChatGPT on the web. Install it from chatgpt.com/plugins, then type @ and choose Nylon in a chat.
What you can ask ChatGPT with Nylon
Type @, choose Nylon and start your question with “Using Nylon”. ChatGPT searches Nylon’s library before it answers.
Employee benefits
“Using Nylon, when is a gift to an employee a tax-free trivial benefit, and what limit applies to directors?”
Corporation tax
“Using Nylon, how does marginal relief work for company profits between £50,000 and £250,000?”
Capital gains tax
“Using Nylon, what rate of capital gains tax applies to Business Asset Disposal Relief from 6 April 2026?”
VAT
“Using Nylon, when must a business register for VAT? Cite VATA 1994 and VAT Notice 700/1.”
Trusts
“Using Nylon, how is the ten-year anniversary charge on a discretionary trust worked out?”
Penalties
“Using Nylon, what counts as a reasonable excuse for a late filing penalty? Cite the tribunal decisions.”
How Nylon works inside ChatGPT
01
You ask in ChatGPT
Type @ and choose Nylon, then start your question with “Using Nylon”.
02
ChatGPT searches Nylon
ChatGPT runs up to five keyword and meaning-based searches at once across UK tax legislation, HMRC guidance and tax case law.
03
ChatGPT reads and cites
ChatGPT reads the section, ruling or judgment itself, answers from its text and links each citation to the source in Nylon.
How to add Nylon to ChatGPT
You need a Nylon Adviser or Elite seat. Your ChatGPT plan and workspace settings decide whether you can add plugins.
From the plugin directory
Open chatgpt.com/plugins and search for Nylon.
Open the Nylon listing and choose Install Plugin.
Sign in to Nylon and choose Allow access.
Start a new chat, type @ and choose Nylon.
Server URL, if you add Nylon by URL
https://mcp.usenylon.com/mcp
Start each question with “Using Nylon” so ChatGPT searches Nylon before it answers.
Business, Enterprise and Edu
Workspace admins decide which plugins members can install and who can add custom MCP servers. If you can’t find Nylon, ask your ChatGPT admin.
Add by URL
In chatgpt.com/plugins, choose + → Add custom MCP server. Under Connection, choose Public endpoint and paste the server URL, choose OAuth, then Create as a plugin and install it.
ChatGPT on its own vs ChatGPT with Nylon
Where answers come from
Its training data and, when it searches, the open web
Nylon’s UK tax library: legislation, HMRC guidance and tax case law
Citations
Web links, if any, that can be general or hard to check
Each citation links to the document in Nylon
What ChatGPT reads
Snippets of web pages
The full text of the section, ruling or judgment
Who controls access
Your ChatGPT account and workspace
Your Nylon sign-in, and your Nylon admin can switch connections off
What’s in Nylon’s UK tax library
Nylon’s UK library is built for tax. It draws on legislation.gov.uk, GOV.UK and Find Case Law.
Legislation
The core UK tax Acts and regulations, including ITEPA 2003, ITTOIA 2005, ITA 2007, CTA 2009 and 2010, TCGA 1992, IHTA 1984, VATA 1994, TMA 1970, selected Finance Acts to 2026, and Scottish and Welsh devolved taxes.
HMRC guidance
HMRC’s internal manuals, VAT Notices, Tax Information and Impact Notes, and Making Tax Digital guidance from GOV.UK.
Case law
Decisions involving HMRC from the First-tier Tribunal (Tax), Upper Tribunal, High Court, Court of Appeal and Supreme Court.
Read-only, and under your firm’s control
Nylon for ChatGPT gives ChatGPT access to Nylon’s library, and nothing else in your account.
Read-only
ChatGPT can search Nylon’s library and read documents. It can’t upload, edit or delete anything.
Your own sign-in
Each person connects with their own Nylon account. ChatGPT never sees your Nylon password.
Private by design
ChatGPT can’t see your Nylon chat history, folders or saved work, or change account, billing or team settings.
Admin control
Admins can turn off Allow AI tool connections for the whole organisation at any time.
Baqir Hussein, FCCA · Founder & Director, Finex Chartered Certified Accountants
Nylon for ChatGPT: frequently asked questions
More detail is in the ChatGPT setup guide, or email support@usenylon.com.
Which ChatGPT plans can use Nylon?
Your ChatGPT plan and workspace settings decide whether you can add plugins. On Business, Enterprise and Edu workspaces, an admin or owner controls which plugins are available.
Which Nylon plan do I need?
An Adviser or Elite seat. Starter seats don’t include the AI connector.
What UK sources can ChatGPT search?
UK tax legislation, HMRC manuals and guidance, and tax decisions from the tribunals and courts.
How is this different from asking ChatGPT about UK tax directly?
On its own, ChatGPT answers from its training data and, when it searches, the web. With Nylon, it searches a curated library of primary sources, reads the documents and links each citation to the source so you can check it.
Can ChatGPT change anything in Nylon?
No. The plugin is read-only. ChatGPT can search and read documents, but it can’t upload, edit or delete anything, or see your chat history, folders or saved work.
Should I install from the directory or add Nylon by URL?
Use the plugin directory if you can: search chatgpt.com/plugins for Nylon and choose Install Plugin. If your workspace allows custom MCP servers, you can add https://mcp.usenylon.com/mcp by URL instead.
How do I make Nylon available to my whole firm?
On ChatGPT Business, Enterprise and Edu, workspace admins control which plugins members can install. Each person then connects with their own Nylon sign-in, and Nylon admins control access with Allow AI tool connections.
How do I disconnect Nylon from ChatGPT?
Remove Nylon from your ChatGPT plugins. A Nylon admin can also turn off Allow AI tool connections for the whole organisation.
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Last updated 21 October 2026. ChatGPT is a trademark of OpenAI. Nylon isn’t affiliated with or endorsed by OpenAI.