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Nylon for Claude
Cited UK tax research, inside Claude
Nylon for Claude connects Claude to Nylon’s UK tax library: tax legislation, HMRC manuals and guidance, and tax tribunal and court decisions. Claude searches and reads the sources, then cites each one with a link you can check. Set it up in about two minutes with a Nylon Adviser or Elite seat.
Read-only access
Your own Nylon sign-in
SOC 2 Type 2
ISO 27001
Claude
Nylon connected
Using Nylon, when is s455 tax due on an overdrawn director’s loan account?
Searched Nylon’s UK tax library
Read 2 documents
If the loan is still outstanding nine months after the end of the accounting period, s455 tax is due the next day: nine months and one day after the period ends [1]. The rate is 35.75% for loans made on or after 6 April 2026, and 33.75% for earlier loans [2].
1
Corporation Tax Act 2010, s 455
Nylon
2
HMRC Company Taxation Manual, CTM61505
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Illustrative example
Nylon for Claude at a glance
What it is
A read-only connector that adds Nylon’s search and documents to Claude, built on the Model Context Protocol (MCP).
What Claude 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, on any Claude plan: Free, Pro, Max, Team or Enterprise.
Where it works
Claude on the web, Claude Desktop, Cowork, the Claude mobile apps and Claude Code.
What you can ask Claude with Nylon
Start your question with “Using Nylon” and Claude will search Nylon’s library before it answers.
Corporation tax
“Using Nylon, when is s455 tax due on an overdrawn director’s loan account, and when is it repaid?”
Making Tax Digital
“Using Nylon, who has to use Making Tax Digital for Income Tax from April 2026, and what are the income thresholds?”
Inheritance tax
“Using Nylon, how does the £2.5 million allowance for business and agricultural property relief work from 6 April 2026?”
VAT
“Using Nylon, how is VAT charged on private school fees from 1 January 2025? Cite HMRC’s guidance.”
R&D relief
“Using Nylon, under the merged R&D scheme, who claims relief for contracted-out R&D?”
Tax disputes
“Using Nylon, what have the tribunals and courts said about staleness in discovery assessments? Cite the cases.”
How Nylon works inside Claude
01
You ask in Claude
Switch Nylon on under + → Connectors, or start your question with “Using Nylon”.
02
Claude searches Nylon
Claude runs keyword and meaning-based searches across UK tax legislation, HMRC guidance and tax case law.
03
Claude reads and cites
Claude opens the documents it needs, answers from their text and links every citation to the source in Nylon.
How to add Nylon to Claude
You need a Nylon Adviser or Elite seat and any Claude plan. The Free plan allows one custom connector.
Free, Pro and Max
In Claude, open Customize → Connectors.
Choose + Add, then Add custom connector.
Name it Nylon, paste the URL below and choose Continue.
Under OAuth client, choose Register automatically, then Add.
Sign in to Nylon and choose Allow access.
Connector URL
https://mcp.usenylon.com/mcp
In a chat, choose + → Connectors and make sure Nylon is switched on.
Claude on its own vs Claude with Nylon
Where answers come from
Its training data and, if you turn it on, web search
Nylon’s UK tax library: legislation, HMRC guidance and tax case law
Citations
Can be missing, general or hard to check
Each citation links to the document in Nylon
What Claude reads
Snippets of web pages
The text of the Act, guidance or judgment itself
Who controls access
Your Claude account
Your Nylon sign-in, and your 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 Claude gives Claude access to Nylon’s library, and nothing else in your account.
Read-only
Claude 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. Claude never sees your Nylon password.
Private by design
Claude 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.
“There isn’t a day when we don’t use Nylon. The research is so specific, complete, and trustworthy.”
Baqir Hussein, FCCA · Founder & Director, Finex Chartered Certified Accountants
Nylon for Claude: frequently asked questions
More detail is in the Claude setup guide, or email support@usenylon.com.
Which Claude plans work with Nylon?
All of them: Free, Pro, Max, Team and Enterprise. The Free plan allows one custom connector.
Which Nylon plan do I need?
An Adviser or Elite seat. Starter seats don’t include the AI connector.
What UK sources can Claude search?
UK tax legislation, HMRC manuals and guidance, and tax decisions from the tribunals and courts.
How is this different from asking Claude about UK tax directly?
On its own, Claude answers from its training data and, if you turn it on, 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 Claude change anything in Nylon?
No. The connector is read-only. Claude can search and read documents, but it can’t upload, edit or delete anything, or see your chat history, folders or saved work.
Does it work in Claude Desktop, mobile and Claude Code?
Yes. Add Nylon once and it’s available in Claude on the web, Claude Desktop and Cowork, and in the Claude mobile apps the next time you sign in. In Claude Code, run: claude mcp add --transport http nylon https://mcp.usenylon.com/mcp
How do I set it up for my whole firm?
On Claude Team or Enterprise, an Owner adds Nylon once in Organization settings → Connectors. Each person then connects with their own Nylon sign-in. Nylon admins control access with Allow AI tool connections.
How do I disconnect Nylon from Claude?
Remove Nylon in Customize → Connectors. A Nylon admin can also turn off Allow AI tool connections for the whole organisation.
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Developer docs ↗
Endpoint, sign-in, tools and errors.
Last updated 21 October 2026. Claude is a trademark of Anthropic. Nylon isn’t affiliated with or endorsed by Anthropic.