Made for UK practices, chambers and firms
Your client keeps their name. The AI gets [PERSON_1] instead.
Start today with Free: no account, no card, set up in a minute
Works with ChatGPT, Claude, Copilot and any other AI tool.
Outlook, the browser, spreadsheets or a passport scan: Nonimo holds client details back from the AI in each of them.
In the centre, a short sample with its client details swapped for placeholders. Around it, four cards: one key in any desktop app, the Chrome and Safari extension for ChatGPT, Claude and Gemini, Word, Excel and PDF files, and copies of passports and driving licences.
Select text in Outlook, Word or Teams, press your key and client details become placeholders.
Watch it happen →Client details in a spreadsheet or letter come out before you upload it to an AI tool.
Anything pasted into ChatGPT, Claude or Gemini goes in redacted, with the Nonimo app on Mac or Windows.
More on the extension →Hide the fields you pick and stamp the copy with its purpose and the month, on your own device.
ID copies, step by step →Nonimo trained it to spot personal details even when nothing flags them: a stray first name, a joinery firm mentioned halfway through a sentence.
See how it reads →When your firm's own software talks to an AI provider by API, Nonimo Gateway holds the personal data back on your server before each call.
Discover the Gateway →[nonimo]
Email · Outlook
Your original
Hi Callum Ashvenridge, can you call me on 07700 900417 about the lease renewal?
Sent to the AI
Hi [PERSON_1], can you call me on [PHONE_1] about the lease renewal?
fees.xlsx · row 22
Your original
Client: Fiona Thrimbleworth · Email: fiona.t@example.org · Ref.: INV-2026-0738
Sent to the AI
Client: [PERSON_1] · Email: [EMAIL_1] · Ref.: [REFERENCE_1]
Nonimo's own model
Your original
Rang Gareth Pennock back about the Brindlecombe Joinery snagging list; he wants it by Friday.
Sent to the AI
Rang [PERSON_1] back about the [COMPANY_1] snagging list; he wants it by Friday.
Nonimo Gateway
Your original
Summarise the complaint from Ffion Aldermere and send a reply to ffion.a@example.co.uk today.
Sent to the AI
Summarise the complaint from [PERSON_1] and send a reply to [EMAIL_1] today.
Passport · data page
The AI never sees your dataReversibleNo cloud involved
Our own model
It reads a whole sentence the way a colleague would, and picks out your clients' details before they leave your computer.
Here's the engagement letter for Bethan Corrigall at Larkhollow Mechanical, NI number QQ 12 34 56 C, for you to look over.
Here's the engagement letter for [PERSON_1] at [COMPANY_1], NI number [NINO_1], for you to look over.
Not someone else's general-purpose model with our badge on. We trained it ourselves, for a single job.
It knows a person or a business when it sees one, with no Mr before the name and no Ltd after it.
It runs on your computer, so the text you write never passes through Nonimo's servers.
Choose a practice and compare the two sides: your original, and the version the AI receives.
One key, roughly a second, and it all happens on your own computer. Nonimo lifts client names, NHS numbers, UTRs, VAT numbers and postcodes from a document before ChatGPT, Claude or Copilot get to see it, and restores the real details once the reply is back. Choose a practice below; every document is invented.
NI numbers, NHS numbers, UTRs and client names are covered as standard.
Before a letter or a matter file reaches ChatGPT, Claude or Copilot, Nonimo swaps NI and NHS numbers, UTRs, names and postcodes for placeholders locally, and every original reappears when the AI replies.
| Reference | Typically found in | What the AI sees |
|---|---|---|
| NHS number | GP letters, referrals, discharge summaries | [NHS_NUMBER_1] |
| National Insurance number | Payslips, P60s, HMRC letters | [NINO_1] |
| Unique Taxpayer Reference (UTR) | Self Assessment returns, HMRC correspondence | [UTR_1] |
| VAT registration number | Invoices, VAT returns | [VAT_NUMBER_GB_1] |
| Company registration number | Letterhead footers, email signatures, contracts | [COMPANY_NUMBER_GB_1] |
| Bank account number | Completion statements, payment instructions | [BANK_ACCOUNT_GB_1] |
| Bank sort code | Bank statements, Direct Debit mandates, supplier invoices | [SORT_CODE_1] |
| CHI number (Scotland) | NHS Scotland referrals, prescriptions, hospital letters | [CHI_NUMBER_1] |
| H&C number (Northern Ireland) | HSC referrals, GP records, prescriptions | [HC_NUMBER_1] |
| County Court claim number (online money claims) | Claim forms, defences, directions questionnaires | [COUNTY_COURT_CLAIM_1] |
| High Court claim number | Claim forms, sealed orders, witness statements | [HIGH_COURT_CLAIM_1] |
| Unique pupil number (UPN) | Pupil records, common transfer files, SEND referrals | [UPN_1] |
| DBS certificate number | Personnel files, single central records, onboarding checklists | [DBS_CERTIFICATE_1] |
| DBS Update Service ID | Job applications, staff files, status check records | [DBS_UPDATE_ID_1] |
| Immigration Health Surcharge (IHS) reference | Visa applications, surcharge payment receipts | [IHS_REFERENCE_1] |
| Asylum support reference | Home Office support letters, ASF1 applications, appeal bundles | [ASYLUM_SUPPORT_REF_1] |
| Home Office share code | Right to work and right to rent checks, new starter forms, tenancy applications | [SHARE_CODE_GB_1] |
| Driving licence number | Hire agreements, insurance claims | [DRIVING_LICENCE_1] |
| Postcode | GP registration forms, claim forms, KYC checklists | [POSTCODE_1] |
| Full postal address | Letterheads, client care letters, tenancy agreements | [ADDRESS_1] |
On top of these: client names, dates of birth, passport numbers, IBANs, card details, email addresses and phone numbers, wherever in the text they appear.
A landlord, an employer or a new bank wants a copy of your passport or driving licence? Nonimo hides the parts they have no use for, right on your computer, so the copy you send carries only what was asked for.
Click or tap any bar to reveal the detail beneath
A right to work or tenancy check may need every detail showing. In that case Nonimo prints the purpose and the month across the copy, which makes it far less useful to anyone hoping to reuse it.
For teams
Your IT team installs it across every machine at once, and a signed log shows you what was kept back.
IT deploys it to every Chrome browser in the firm from the management console they already use. Nobody has to remember to turn it on.
The app keeps a tally, on each computer, of how many details of every kind it held back. You download a PDF signed by Nonimo for whichever period you choose.
The desktop app runs on Mac and Windows. The browser extension goes onto every Chrome browser in the firm through enterprise policy, so your IT team or managed service provider can push it to every desk from the console they already work in.
Any computer can create a usage report, signed digitally, of how many names, addresses, bank details and reference numbers it held back over a period you choose. The text and the details themselves are never kept. Whoever receives the report can confirm on nonimo.ai that Nonimo issued it and that nobody has altered it.
For in-house software that calls an AI provider by API, there is Nonimo Gateway, which you install on your own servers.
Client details become placeholders on your computer, a safeguard UK GDPR recognises by name.
Nonimo replaces client names and reference numbers with placeholders on your computer before anything is pasted. UK GDPR treats that step, pseudonymisation, as a safeguard in itself, and the four duties below sit alongside it.
Article 28
Team and enterprise AI plans can include terms that meet Article 28. A personal login sits on consumer terms instead, which leaves the firm with no processor agreement to point to.
Transfers
The big AI providers process data outside the UK, so pasting into one is normally a restricted transfer. The UK-US data bridge only applies where the US company holds a current Data Privacy Framework certification: look it up on the list rather than take it on trust.
Article 4(5)
Text with its names and numbers swapped for placeholders is pseudonymised, not anonymous, and it remains personal data. The Information Commission, the UK's data protection regulator, says plainly that removing direct identifiers will not make a file anonymous.
Article 33
If personal data goes astray and the people involved are put at risk, the firm must tell the regulator within 72 hours of finding out.
Taking identifiers out before anything is sent is data minimisation, the first thing the regulator looks for, and Nonimo turns it into routine: it runs on the machine itself, every single time. What remains is still personal data, so your lawful basis, provider contract and records of processing carry on as before. For a tool-by-tool run-through, see our checklist for UK firms choosing an AI tool.
This is a summary, not legal advice. Solicitors also have the SRA to answer to: its August 2026 warning notice cautions that AI tools, paid-for or not, may fall short of what client confidentiality demands. Accountants have the ICAEW Code of Ethics to follow.
[IBAN_1] [EMAIL_1] [PHONE_1] [BIRTH_DATE_1] [PERSON_1] Pick a profession for its own page: the reference numbers on its paperwork, what Nonimo masks before any of it gets to AI, and why.
Straight answers on UK GDPR, provider contracts and where client data ends up, for the partner or practice manager who signs off AI at work.
Nonimo is an app for Mac and Windows that replaces client details with tags before they reach an AI tool. Names, NHS numbers and bank details become tags like [PERSON_1] on your own computer, and copying the answer brings the real details back.
Nonimo closes the four gaps through which client details usually reach AI. They are selected text in any app; pastes into ChatGPT, Claude or Gemini; Word, Excel and PDF uploads; and passport or driving licence copies.
No client data goes to Nonimo, because redaction is done locally on your machine. The redacted text, still personal data, does go on to the AI provider you paste it into, and whether it reaches the US depends on that provider.
Nonimo pseudonymises data, and deliberately so. Names and account numbers are swapped for tags like [PERSON_1] before the text leaves your machine, then restored when the reply lands. Anonymous text could never be turned back, so the AI's draft could never name your client.
Nonimo helps with a real part of UK GDPR. Lifting identifiers out before pasting shrinks what reaches the AI provider: the data minimisation principle of Article 5(1)(c) in practice. The lawful basis, Article 28 contract, transfer route and record of processing stay with you.
Which AI tools are UK GDPR compliant? How to use them at work
A business ChatGPT plan fixes the paperwork, not the content. It can bring the Article 28 processor agreement, yet whatever you paste still lands with the provider, identifiers and all. The SRA's warning notice says much the same to solicitors.
Yes, you can use Nonimo with Copilot in exactly the same way as with ChatGPT, Claude or Gemini. Redaction takes place before the paste, so you keep using the Copilot licences the firm has already bought.
Yes, Nonimo has an extension for Chrome and Safari. It looks after ChatGPT, Claude and Gemini alongside the Nonimo app on a Mac or Windows PC. Chrome users get it from the Chrome Web Store; the Safari version comes with the Mac app.
Use Nonimo's online ID document tool to redact and watermark a copy of your passport or driving licence. It takes a photo or scanned PDF, runs in your browser, never sends the document to a server and needs no account.
Nonimo has a Free plan that redacts a monthly maximum of 100,000 words, with no card details and no sign-up. Personal and Team drop the limit for £12.90 monthly or £129 annually, and Team is that price per head, for groups from 2 to 49.