Duolign is a trading name of JeffNet Ltd ("Duolign", "we", "us"), a company registered in England & Wales (company no. 16842612; registered office 73 Balmoral Drive, Southport, PR9 8QH), registered with the UK Information Commissioner's Office (ICO registration number ZC263369). We are the data controller for the personal data described in this policy. This policy explains what we collect, why, and the choices and rights you have — including how to delete everything, yourself, at any time.

1. What we collect

Account & household data, which you give us directly: your email address, a display name, your household's structure (you and your partner), how you split shared costs, your payday pattern, and the bills, budgets, goals and debts you set up.

Financial data, from the bank statements you upload and the figures you enter yourself: balances and transaction history for those accounts.

Device & usage data: a push-notification token (so we can notify you), basic device type, and app diagnostics (crash and error logs) so we can fix problems.

We do not collect your location, your contacts, or browsing history outside the app.

2. AI-assisted statement reading

If you upload a PDF bank statement from a bank we don't yet read with a dedicated, rule-based parser, its text is read by an AI language model instead, to extract a list of transactions. This is a model we run ourselves, not a third-party AI product — your statement data is never sent to an external AI company such as OpenAI, Google or Anthropic for this.

Before any text reaches the model, we strip out account numbers, sort codes, card numbers, and your name and address automatically — only the transaction lines themselves (dates, descriptions, amounts) are sent. The model runs on cloud servers located entirely within the European Economic Area (EEA); this data never leaves the EEA for this purpose, and is never used to train any model.

The model's output is never trusted on its own: every transaction it returns is checked, deterministically, against the statement's own printed totals before anything is saved. A statement that doesn't reconcile is rejected rather than silently imported wrong.

3. Why we use it, and our legal basis

• To provide the service (performance of our contract with you): calculating your household's payday split, tracking bills and debts, running the projections you ask for, and the two-person approval workflow for shared changes.
• To keep the service secure (our legitimate interest): detecting misuse, abuse, and unauthorised access attempts.
• To deliver a voucher a business gave you (our legitimate interest): if a partner business sends you a Duolign voucher, it gives us your email address. We use it only to email you the voucher and to know which business it came from.
• To let a business know it was you (your consent): if you redeem a voucher a partner business gave you and tick “Let <business> know it was me”, we show that business the email address you redeemed with, next to that voucher. Leave it unticked and the business only sees that the voucher was redeemed.
• To send you news and offers (your consent): only if you opt in yourself — through the link in a voucher email, the redeem page, or Settings → Notifications in the app — and you can switch it off there at any time. Every such email includes a way to unsubscribe.
• To contact people on our waiting list (your consent): if you join our waiting list on this website, we use your email address to tell you when Duolign launches. If you tick the box, we’ll also send you occasional money tips and launch news, and you can unsubscribe at any time.

We do not use your data for advertising, and we do not sell personal data to anyone, ever.

4. Who sees it

Your partner sees the data your household shares by design — that's the point of a joint budget. Joint accounts are always shared; you can keep any of your own accounts private from your partner.

A partner business that gave you a voucher sees whether it has been redeemed, and when, plus its own note of who it gave the voucher to. It sees the email address you redeemed with only if you choose to let it know. It never sees your financial information or how you use the app: figures such as how many couples are still using Duolign are shown to it only as totals across all its vouchers, and only once at least five couples have redeemed.

We share data with a small number of infrastructure providers who process it on our behalf, under contract, and only as needed to run the service:

• Supabase — our database and authentication provider, hosted in the EU (AWS, Ireland).
• Railway — hosts the servers that run the app, in the EU (Amsterdam, Netherlands).
• RunPod — our cloud GPU hosting provider; runs the AI model described in section 2, within the EEA only; it never sees who you are, only redacted statement text.
• Google Firebase — delivers push notifications to your device.
• Resend — delivers the emails we send: notifications to us when you contact us (in-app feedback, a deletion request, or joining the waiting list), containing your email address and what you wrote; a voucher a partner business asks us to email you; and emails to partner businesses (section 13). Based in the US; no financial data is ever sent through it.
• RevenueCat — if you buy Premium in the app, records the subscription so both of you get it. It receives your household's ID (a random code, never your name, email or any financial data) and the purchase details from Apple or Google. Based in the US. Apple and Google take the payment themselves, under their own privacy policies; we never see your card details.
• Stripe — takes card payments from businesses buying voucher packs (section 13). It never receives couples' data. Based in Ireland, with some processing in the US.
• Google Workspace — our email, used to write to businesses about the partner programme (section 13).
• Sentry — receives crash and error reports from the app and our servers so we can fix problems, hosted in the EU (Germany).

None of these providers may use your data for their own purposes. We do not share data with data brokers, advertisers, or any other third party.

5. How long we keep it

We keep your household's data for as long as your household is active, so the app keeps working correctly, unless you delete your account or household outright. Waiting-list emails are kept until we've told you Duolign has launched, or for as long as you stay subscribed to money tips and launch news, or until you ask us to remove them. An email address a partner business gave us to send you a voucher is deleted once that voucher expires unused (a year after it was issued) or is withdrawn, unless you've opted in to hear from us; if you redeem it, it's simply your account's own address, and goes when your household is deleted.

6. Your rights — including deleting everything yourself

Under UK GDPR you have the right to access, correct, delete, restrict, or receive a copy of your personal data, and to object to certain processing. For most of these, you don't need to email anyone:

Don't have the app installed, or would rather not reinstall it just to leave? Use our Delete My Data form instead — we'll verify it's really you, then erase your data the same way.

For anything else — a copy of your data, a correction, or a question about how we've used it — email privacy@duolign.co.uk. We'll respond within one month.

7. Security

See our Security & Encryption page for the detail: encryption in transit and at rest, and biometric app protection.

8. International transfers

Your data is primarily stored within the EU, including the AI-assisted statement reading described above (section 2), which never leaves the EEA. Google Firebase (push notifications) may process limited device data outside the UK/EEA; where it does, this happens under Google's standard contractual clauses and equivalent safeguards recognised under UK GDPR. Resend (email notifications, section 4) stores the email address and message it delivers in the United States, under the EU standard contractual clauses as amended by the UK Addendum; Resend is also certified under the EU-US Data Privacy Framework and its UK Extension. RevenueCat (in-app subscriptions, section 4) processes subscription records in the United States, under the EU standard contractual clauses as amended by the UK Addendum.

9. Cookies & this website

This marketing website (duolign.co.uk) does not use tracking or advertising cookies. If you join the waiting list, your email address is sent directly to our database provider to be stored; no analytics or third-party tracking scripts run on this page. The Duolign app itself is a native mobile app and does not use browser cookies.

10. Children

Duolign is intended for adults (18+) managing a shared household. We do not knowingly collect data from anyone under 18.

11. Changes to this policy

We'll update the date at the top of this page when this policy changes, and tell you in-app if a change is material.

12. Contact & complaints

Questions or requests: privacy@duolign.co.uk. If you're unhappy with how we've handled your data, you can also complain to the UK Information Commissioner's Office (ICO) at ico.org.uk. Our own ICO registration number is ZC263369.

13. Partner businesses and business contacts

This section is for businesses rather than couples: businesses that give Duolign vouchers to their clients, and businesses we contact about doing so.

If your business has a partner dashboard, we hold your business name and type, your main contact's name, email address and postcode, the email addresses of colleagues you add, a record of when you accepted our partner terms, the packs you've bought, your vouchers and how each was handed out, and the notes you write on them. Card payments are taken by Stripe, which sees your card details; we never do. We use this to run your dashboard, send your vouchers, sign-in links and the monthly summary, and keep accounts. Our legal basis is our contract with your business, our legal obligations for purchase records, and our legitimate interest in running the programme.

If we've emailed your business about the programme, we hold its name, type and location, the business email address we found, and where we found it (normally your own website), with a record of what we sent and any reply. We only email limited companies and LLPs this way; we contact sole traders and partnerships only by hand. Our legal basis is our legitimate interest in telling relevant businesses about the programme. Every email says where we found you and how to opt out.

How long we keep it. A business we emailed that didn't join is deleted 12 months after our last email. If you ask us not to contact you, we keep your email address only on a do-not-contact list, so we never email you again. Dashboard details are kept while your dashboard is open. When a business leaves, its notes are deleted, and it can ask us to delete its contact details, team and notes as well. Purchase records are kept for six years for tax, without contact details if you've asked us to delete them.

Your rights. You have the same rights as in section 6. From your dashboard you can download everything we hold about your business, and leave the programme and delete your details. To stop hearing from us, reply "no thanks" to any email we've sent, or email privacy@duolign.co.uk and we'll remove you.

What a business sees about the couples it gives vouchers to is set out in section 4.