Free beta UK Self Assessment for employees with company shares
Your shares get taxed in two places. Nothing tells you the number.
- Payslip · month 12 · RSU vest 12,480.00 ✓
- Release confirmation · broker · same date 12,480.00 ✓
- Payslip chain · pay to date, 12 of 12 186,159.16 ✓
- P60 · pay for the year 186,159.16 ✓
Four documents from three organisations. One number. Rounded down to the pound, the way the box takes it.
A vest is pay on your payslip and a disposal at your broker. An ESPP purchase has a cost you were never shown. Somewhere in that pile of PDFs is the figure HMRC is waiting for. Tracepaper reads the documents on your own device, checks every figure against the other documents that should agree with it, and shows you the box values with the working behind each one.
Get a free beta pass How it works
Free while it is in beta. One field, no account, no card, and the pass comes back on this page. No cookies, no trackers, nothing loaded from anyone else.
It is a beta, and here is what that means. Reading has been tested to the penny on documents from two employers. Yours may be the first documents of their kind it has seen — what happens when that is so is written down rather than glossed over.
Who it is for
If any of this is your evening in January
- “My vests show up as pay and as a sale. I can’t tell whether I’m being taxed twice.”
- “Some shares were sold automatically to cover the tax. I don’t know if I have to report that.”
- “My ESPP was bought at a discount and I have no idea what my cost is meant to be.”
- “There are four vests, three sales and a dividend in dollars, and my return wants pounds.”
- “I went over £100,000 and my personal allowance started disappearing.”
- “I want to know in September how much pension allowance I have left, not next April.”
Built for a UK employee, paid through PAYE, holding RSUs or ESPP shares at a US or UK broker, in Self Assessment because of them. It is not built for the self-employed, for landlords, or for anyone whose return is mostly something else.
What it does not do yet
Even if you fit that, before you rely on a figure, know what it does not compute:
- Scottish income tax. It can read your tax code but will not work out the bill.
- Anything beyond RSUs and ESPP. Not share options, SAYE, SIP, CSOP, EMI, or shares under a section 431 election.
- A year split by residence, the remittance basis, or foreign income and gains. It assumes you are UK resident and domiciled for the whole year.
- Capital gains on anything but listed shares. A second home, a buy-to-let or crypto will leave the gains figures incomplete.
- The student loan you owe through Self Assessment. It copies across what your employer deducted; it does not calculate what is owed on top.
- The lower annual allowance that applies once you have started drawing a pension.
- A final salary or career average pension. Only defined contribution schemes are worked out.
- Property income, self-employment, trusts or partnerships.
How it works
Three steps, and the second one is the product
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Put the documents in
Payslips, P60, P11D, P45, release and trade confirmations, 1099-B and supplemental statements, pension and ISA statements. They open in your browser and are stored in your browser. The file itself never goes anywhere — see what leaves your device, which is one thing and is not the file.
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Nothing is believed from a single reading
A figure that has been read once is a guess. Every document is tested against itself and against the other documents that must agree with it — 87 checks, run on your device:
- I01 the payslip’s own payments minus deductions equal the net pay it prints, to the penny
- I03 each month’s pay-to-date equals last month’s plus this month’s, all the way down the chain
- R01 the P60 equals the sum of the payslips — and the P60 is what your employer told HMRC
- R17 the broker’s release confirmation matches the RSU line on the payslip for the same date
- — tax and National Insurance, recalculated from the printed tax code and category, match the printed figures
When a check fails you are shown both sources side by side and asked which is right. A mismatch is never resolved quietly, and a figure is never changed behind your back.
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Take the figures and the working
Box values for the return, a computation in which every number names the document, the page and the box it came from, and your pension allowance position for the year you are actually in. You type the figures into HMRC’s own service, or hand the pack to your accountant.
Run those three steps on your own documents — get a free beta pass →
Privacy
One thing leaves your device. Here is exactly what it is.
Stays on your device
Every document you add, every figure read out of it, every correction you make, the whole calculation and the finished report. They are stored in your browser and nowhere else. The tax engine runs in the browser too: the same Python that runs on a desktop, compiled to WebAssembly, and checked line by line against the desktop run so the answer does not depend on where it was worked out.
There is no account, no password, and no database holding your financial life. If you clear your browser storage, it is gone, which is why the backup is a file you keep.
Leaves your device
A picture of one page, to be read. Before it goes, your browser blacks out your name, National Insurance number, address, employee number and bank details, and stamps the image “Redacted copy — not an original document”. You see the redacted image before it is sent and can black out more of it.
That image travels over an encrypted connection, through a relay we run that stores nothing and logs nothing, to Anthropic’s Claude API, which reads the figures off the page and sends them back. Nothing else is forwarded — not your email, not an account identifier, because there isn’t one.
What we will not claim
- Redaction is a best effort with a step where you check it, not a guarantee. An unusual layout can hide something. That is why you see the image before it is sent.
- Anthropic’s stated default is that inputs are deleted within 30 days, with content flagged by their safety systems kept longer. A zero-retention agreement is available by negotiation and we have not signed one yet. Until we do, the 30 days is the honest answer and this page will say so.
- Your figures are not used to train any model, ours or anyone else’s, and we do not sell data. What we keep, by default, is a fingerprint of the page layout, the names of the fields a check could not confirm, counts of how far you got through the app and how many days you used it on, and which family of browser and system you are on — no amounts, no dates finer than the tax month, no names, no version numbers. You can turn that off and everything still works.
The full privacy notice and terms of use are published here. They have not yet been through a solicitor, and the controller’s legal name, address and contact email are shown on them as marked blanks until they are settled — both facts are stated at the top of each page rather than left for you to find out. What is above is a summary written to match them, not a replacement for them.
Read it, then decide. The pass is free and comes back on this page →
What you get
Box values, the working behind each one, and your pension position
Self Assessment box values
Example · 2025-26 · test fixture| Form | Box | What it is | Value |
|---|---|---|---|
| SA102 | 1 | Pay from this employment | 186,159 |
| SA102 | 2 | UK tax taken off that pay | 64,314 |
| SA108 | 23 | Number of disposals | 7 |
| SA108 | 24 | Disposal proceeds | 29,857 |
| SA108 | 25 | Allowable costs | 29,126 |
| SA108 | 26 | Gains before losses | 1,096 |
| SA106 | 2 | Foreign tax credit relief on dividends | 57 |
Share matching in the right order — same day, then the following 30 days, then the Section 104 pool — with every dollar amount converted at the rate for its own date. Dividends and the 15% US withholding are carried through to the foreign pages.
A computation that shows its working
Every figure in the pack carries the document, the page and the box it was read from, and the rule that turned it into a return line. If HMRC’s own calculation differs from this one, the working is where you find out why — and HMRC’s figure is the one that counts.
SA102 box 1 ← P60 pay_total_for_year 186,159.16, rounded down · agrees with the final payslip’s pay-to-date to the penny
Your pension allowance position
What you have used this year across salary sacrifice, net pay and relief at source, what your employer has added, your annual allowance — tapered if your adjusted income is over £260,000 — and the carry-forward still available from the three earlier years, oldest first, with the slice that lapses next marked.
You can also move a number and see the arithmetic: if you contributed a further £5,000 to a registered pension scheme in 2025-26, this calculation shows income tax of £A instead of £B, and £C of annual allowance remaining.
That is a calculation from figures you have confirmed. It is not personal advice and not a recommendation to pay into any pension. It does not check whether you are eligible to contribute, or how much a scheme will accept. If you want advice on whether or how much to contribute, speak to a regulated financial adviser, or use MoneyHelper, the free government-backed guidance service.
What it is not
The things this does not do, said plainly
- Not tax advice
- It calculates from the documents and confirmations you give it. It does not weigh up your circumstances or tell you what to claim, and it is not a substitute for a qualified tax adviser or accountant.
- Not financial advice, and not an authorised firm
- We are not authorised or regulated by the Financial Conduct Authority. Nothing here is a personal recommendation, and nothing here is an inducement to invest in or contribute to any product.
- Not a filing service
- It produces the figures and a sheet telling you what to type where. You file your own return through HMRC’s service, or your accountant does. Nothing is submitted to HMRC on your behalf.
- Not HMRC, and not connected to HMRC
- An independent tool. HMRC’s own calculation is always the one that counts.
- Not yet tested on your employer’s payslip
- This is a beta. Reading has been tested to the penny on documents from two employers — 165 of 165 fields read correctly on one person’s year, and 100% of the tax-driving fields across the 36 genuine documents in the last measured run. Yours may be the first documents of their kind we have seen. When the app meets a layout it does not know, it asks you one question about that document, with every figure shown where it is printed on your own page — and the figures are cross-checked against each other before you are asked anything.
- Not everything, in the first release
- England, Wales and Northern Ireland income tax. Scottish rates, SAYE, SIP and share options are not in the first release. Nor are property or self-employment income.
Questions
The six questions people ask before they upload anything
- Is it safe to put my payslip into this?
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The design is the answer, not the promise. Your documents are opened and kept in your own browser; there is no account and no database of your financial life on our side, because there is nowhere for one to be. One page image leaves, blacked out, and you see it blacked out and press send yourself before it goes.
The two things we will not claim: blacking out is a best effort with a step where you check it, not a guarantee; and the redacted image is read by Anthropic’s Claude API under their stated 30-day default retention, because we have not signed a zero-retention agreement yet. Both are in the privacy section and in the privacy notice.
- What actually leaves my device?
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One thing: a picture of one page, with your name, National Insurance number, address, employee number and bank details blacked out in your browser first and the image stamped “Redacted copy — not an original document”. It travels encrypted, through a relay we run that stores nothing and logs nothing, to be read, and the figures come back.
Not the file. Not your name. Not an account identifier, because there isn’t one. There is no analytics script on this page or in the app, and nothing phones home. Two requests ever leave, and both wait for something you do: the page you asked to have read, and a small readiness check of the relay — carrying your beta pass and nothing else — when you add a document of your own, save a beta pass or the reader’s address, open the panel that holds them, or ask for a document already here to be sent. Opening the app, reopening it with documents still waiting to be read, and running the example year send nothing at all.
- Who are you?
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to be completed before the beta opens Support is answered by the person who wrote the code, not a ticket queue, and the four questions we ask after the beta are sent by a person too.
The legal entity and its registered address are being settled now and go on the privacy notice and the terms of use before the first user, not after. Where those pages still show a bracketed placeholder, that is a detail not yet decided — shown rather than hidden.
- What does it cost?
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The beta is free. No card, no trial that turns into a subscription, nothing on this page takes a payment. The pass you get is good for 200 documents until 31 December 2026.
Pricing comes after the beta and is deliberately blank until it is decided. When there is a price it will be shown here in full — including what happens if you cancel and how refunds work — before anything is charged, and nobody is charged for something they signed up to while it was free.
- What if it gets a figure wrong?
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It is built on the assumption that it will. A figure read once is a guess, so every figure is tested against the other documents that must agree with it, and each one arrives labelled: corroborated, unchecked, or disagreed. When two sources disagree you are shown both and asked which is right — nothing is resolved quietly behind your back.
Every number names the document, page and box it came from, so you can check it against your own paper. HMRC’s own calculation is always the one that counts. There is a “this figure is wrong” button on every review card; it sends the rule name and the field, and never the figure. Reading has been tested to the penny on documents from two employers — 165 of 165 fields on one person’s year, and 100% of the tax-driving fields across the 36 genuine documents in the last measured run. Yours may be the first documents of their kind we have seen; what happens then is written down.
A wrong reading is one risk; a figure it was never built to compute at all is another — what it does not do yet is listed on this page, not left for you to find out.
- What happens to my email address?
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It goes into one store, kept apart from everything else, which holds your address, the id of the pass we issued you, the date, and — if the link you followed carried one — a tag naming that link, such as ?src=hn. That is the whole record. No name, no documents, nothing about what you upload, no cookie, no IP address, no analytics. It is never joined to anything the relay sees, and the pass itself carries no trace of it.
We use it for two things: to tell you when the beta opens or changes, and to ask you a handful of questions once you have used it. Ask and we delete it. The app itself never sends us a document, whether or not you have signed up. The full version of this is §3a of the privacy notice.
Pricing
Not decided yet, and we would rather show you that than invent a number
Pricing follows the private beta. The shapes below are the ones being considered; the figures are deliberately blank because they have not been set. Nothing on this page takes a payment or asks for a card.
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One tax year
£
Everything for a single year, from documents to box values. One payment.
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Year-round
£/ year
The allowance picture kept current through the year, not rebuilt in January.
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Two people
£/ year
A household where both hold shares. Two separate sets of figures.
When prices are set, they will be shown here in full, including what happens if you cancel and how refunds work, before anything is charged.
Beta
Get a beta pass
One field. Give an email address and a pass comes back straight away, on this page — there is no waiting list and no one on the other end typing it out by hand.
Your beta pass:
Paste this into the app under "Where pages are sent to be read". It is good for 200 documents, until 2026-12-31.
We keep your email address and nothing else — no name, no documents, nothing about what you upload. We use it for two things: to tell you when the beta opens or changes, and to ask you a handful of questions once you have used it. Ask and we delete it. The app itself never sends us a document, whether or not you have signed up.
One more thing goes in that record, and only if it was in the link you followed: a tag such as ?src=hn, so we can tell which link brought people here. It is a word we put in our own links — it says nothing about you, and it is the only thing about your visit that is kept. No cookie is set, no IP address or browser is recorded, there is no analytics on this page, and nothing here is loaded from anybody else. The whole record is four fields: your email address, the id of your pass, the date, and that tag.
Before you type it in: the privacy notice says what happens to that address and to the one page image that ever leaves your device, and the terms of use say what this is and is not. Both are short, and both show what is still blank.
No luck above? Email the waitlist or write to waitlist@tracepaper.co.uk
Status Private beta from late September 2026 with a small number of people who lend a document. Public release planned for 11 October 2026.