We build the data that tests AI, and help you get paid for yours.
UK Tax Gym makes synthetic UK tax tasks that train and test AI agents, marked to the penny. We also help UK companies and insolvency practitioners license real business records to AI buyers, safely, under UK GDPR.
Two sides of the AI data market, one UK team
AI companies need data that's realistic, legal and checked. We make it from scratch, and we help companies that already have it sell it properly.
Synthetic UK tax tasks for AI
Fictional sole traders with a year of messy paperwork. Every answer is known, so every AI attempt is marked exactly.
License your company's records
Support tickets, CRM history, documents and code teach AI how real work is done. We value it, prepare it and run the buyer process.
Know your AI gets UK tax right before it files for real people
Each task is a fictional plumber, electrician or decorator with a full year of bank statements, receipts, invoices and client messages. Your AI prepares the HMRC Making Tax Digital update. We mark every box to the penny.
- Unlimited tasks from one generator, each with an exact answer.
- Marking that can't be gamed: a high score means the books were right.
- 100% synthetic: no real person's data, so nothing to anonymise.
| Allowable | Correct | AI answer |
|---|
A real answer from a leading AI model on one of our tasks (October 2026). The client claims actual van costs, and the AI switched to the 45p-a-mile allowance.
Paperwork as messy as a real client's
Turn on the annotations to see how a good bookkeeper treats each line.
45p a mile, 25p after 10,000, or actual costs × business use. Never both.
Payouts arrive net of fees. Turnover is the gross.
Household items on trade receipts, loans from family.
HMRC's flat rate: £10, £18 or £26 a month.
How AI models score on UK tax
Ranked by tasks fully correct, then by average profit error. Model makers can pay for an official verified run. They pay for the testing, never for the ranking.
What small AI errors add up to at scale
An illustration using the average profit error from our test runs. Errors go both ways: some returns over-claim, others under-claim.
Updates are cumulative, so an early mistake carries through every later quarter.
Show customers your AI is tested on UK tax
Your product sits our held-out exam: tasks never published, marked to the penny. Pass, and display the badge, your score and a link to your public listing.
- A fresh exam every time. Tasks can't be seen in advance.
- Retested on up to four releases a year.
- A full report on every rule you missed.
Learn bookkeeping on real-looking books
The engine that tests AI gives bookkeeping students and new MTD bookkeepers realistic clients to practise on: line drills, full quarterly returns, instant marking and the rule behind every answer.
Practice beta
40 practice clients, line drills and full returns.
Practice
Unlimited clients, progress tracking, weak-spot drills.
Colleges
Class seats and a results dashboard for tutors.
Your company's records are worth something to AI. Find out what in 5 minutes.
AI developers pay for real examples of everyday work: how tickets get resolved, how deals are won or lost, how code gets reviewed. We value your records, prepare them under UK GDPR and run a competitive buyer process. We never hold your raw data, and you approve every buyer and every term.
What you can license
Weights show how much each system adds to value in our model. Direct messages, HR and health records are excluded by default.
What is your company's data worth?
Answer nine questions. No files, no uploads. You'll get a verdict, an indicative range, the five factors behind it and one next step. If your data isn't licensable yet, we'll say so plainly.
Five factors buyers look at
Scale
More staff means more examples. Buyers rarely want under 25 staff.
History
Years of records matter more than headcount. Two years is the floor.
Breadth
Several connected systems beat one. Support, code, CRM and calls weigh most.
Rights and privacy
Clear rights and little customer personal data. Sensitive sectors need specialist clearance.
Buyer fit
English, high-value systems, and records that show outcomes, not bare logs.
From free estimate to getting paid
Free estimate
Nine questions, a verdict and a range in 5 minutes.
Readiness review
Data manifest, rights review, DPIA outline and a firm estimate.
De-identify
Names replaced inside your systems, then a motivated-intruder test.
Buyers compete
Two to four vetted buyers see an anonymised profile and bid.
You approve, get paid
Typically 30 to 60 days from delivery. License the same copy again, non-exclusively.
Buyers we work with, by type
Frontier AI labs
Large volumes of real work to train general agents.
Training-data firms
Intermediaries that clean, package and resell to labs.
Evaluation firms
Realistic records to test AI before release.
Enterprise AI teams
Domain examples to fine-tune internal tools.
Vertical AI start-ups
Sector-specific records for one industry.
Data marketplaces
Platforms that list licensed datasets for many buyers.
Every buyer is vetted, including sanctions checks. We show no buyer logos without their permission.
A failed company's records can be an asset for creditors
An estate with 25 or more staff often holds years of email, chat, tickets and documents that AI buyers pay for. We realise that value for the estate. You keep control, and our commission is disclosed to creditors.
Know which accountancy practices have clients in filing distress
A monthly regional report built from public Companies House and Gazette data: practices with several clients showing filing-distress indicators, and which IP firms already take appointments nearby.
- A flat subscription, never per referral or appointment.
- No director data. The contact is the firm, not a person.
- Signals are filing-distress indicators, not proof of insolvency.
Published prices for everything we do
No retainers on data licensing: you pay only from money you receive.
UK-TaxBench Starter Pack
200 private tasks (50 fictional sole traders × 4 quarters), the full answer key and a marking script. Non-exclusive licence for training and evaluation. Delivered the moment you pay.
Evaluation Starter
- ✓200 marked runs a month
- ✓Full error reports
- ✓Public tasks + 100 private
Evaluation Team
- ✓2,000 marked runs a month
- ✓Full private evaluation set
- ✓Compare releases side by side
Certification
- ✓Held-out exam
- ✓Badge and public listing
- ✓Up to 4 retests a year
Training licences
- ✓Hundreds to thousands of tasks
- ✓Accountant-checked
- ✓Custom agent environments
Verified leaderboard run: £1,500 per model. The public UK-TaxBench is free. Prices exclude VAT.
Free estimate
Verdict, range, five factors and a next step. Plus a free 30-minute readiness call.
Value my dataReadiness review
Export plan, rights review, data manifest, DPIA outline and buyer shortlist. Credited in full if you go ahead. Waived for "Strong candidate" results.
Buyer process and licence
Minimum £5,000, paid only from money received. Above £1m, 8% on the excess. Repeat licences to new buyers at the same rate.
Cleaning and de-identification
We don't mark it up, and we never hold your data.
How data is handledPractice Insight pilot
One region's monthly report and prospect list.
Founding
Then £495/month standard.
Multi-region
Annual plans: 10 × monthly (2 months free).
Estate data
Paid by the estate from realisations, disclosed to creditors. No sale, no fee.
We never pay or receive any fee for the introduction of an insolvency appointment.
Practice
- ✓Unlimited clients
- ✓Progress and weak spots
Colleges
- ✓Class seats
- ✓Tutor results dashboard
Earn with us
Accountants, solicitors and business brokers can refer companies, and qualified accountants can get paid to write and check our tax tasks.
About 1.8% of the deal value. Accountants must disclose the commission to their client and get consent.
A fictional scenario with a trap you've seen in practice, plus the correct treatment.
Confirm answers before tasks ship. Reviewers are named on the benchmark.
Split between contributors to each pack, paid quarterly.
Referral fees go to accountants, solicitors and brokers only. We never pay insolvency practitioners. Task authors must never include real client details.
Research you can use
How AI handles UK tax rules
Which models get MTD right, which rules trip them up and what it costs. Summary free, full report £495.
Selling company data to AI
Prices by company size, who's buying, and the UK GDPR checklist to follow before anything leaves your systems.
Safe by design, on both sides
Our tax tasks contain no real people at all. For real company records, the safeguards are built in, not added later.
We never hold raw data
Records stay in your environment. Buyers never get live logins.
De-identified first
Names and contacts swapped for consistent stand-ins, then a motivated-intruder test.
Exclusions by default
Direct messages, HR and health records are left out.
You approve everything
Every buyer and every term. Buyer exclusivity never longer than 30 to 45 days.
You can object to your data being included in any licence. We honour it.
Selling your data
Is licensing company data legal under UK GDPR?
It can be, with the right steps: a lawful basis, de-identification before anything leaves your systems, a data protection impact assessment and a re-identification test. We build all of that in. Review each deal with your own lawyer.
Do you see my data?
No. Records stay in your environment and are de-identified there. We never hold raw data, and buyers never get live access.
What if my data isn't licensable?
The estimate says so plainly and names the blocker to fix first. Common blockers are under 25 staff, under 2 years of records, a single system, or restrictive client contracts.
Will my staff's private messages be included?
No. Direct messages, HR and health threads are excluded by default, and anyone can object to inclusion.
Can AI models memorise names?
They can, which is why names are replaced before anything leaves, not afterwards.
Should I give a buyer exclusivity?
Not for more than 30 to 45 days. Non-exclusive licences let you sell the same copy to the next buyer.
Can a company in liquidation do this?
Yes, through the insolvency practitioner. Proceeds go to the estate for creditors, and our commission is disclosed.
Tax Gym
What is an AI training environment?
A simulated workplace where an AI practises a task many times and is scored on each attempt. Ours covers UK bookkeeping and tax.
Can we pay to rank higher on the leaderboard?
No. A verified run pays for testing under exam conditions. The score is whatever the model earns, published either way.
Who checks the tax rules?
Every task in a private pack is checked by a qualified UK accountant before it ships.
Is any of this tax or legal advice?
No. We are not a law firm, our tax tasks are training data, and our estimates are indicative, not offers.
Test your AI, or find out what your data is worth.
Both start free. No files, no sales call needed.