These terms govern your use of the dragonfin service, provided by Dragonfire Technologies Limited (company number 16928030). By subscribing to or using dragonfin, you agree to these terms.

1. Definitions

• Service — the dragonfin software and hosted infrastructure that transmits Making Tax Digital (MTD) submissions to HMRC on your behalf. dragonfin is a technology service provider only, not an accountancy firm, not a tax adviser, and not a registered tax agent. See §2.
• Vendor, we, us, our — Dragonfire Technologies Limited, registered in England and Wales, company number 16928030, registered office 21 Thornhill Road, Ickenham, Uxbridge, Middlesex, UB10 8SG. Operating as a technology service provider.
• Customer, you, your — the individual or business who subscribes to and uses the Service.
• HMRC — His Majesty's Revenue & Customs.
• Submission — any tax return, quarterly update, or other filing you send through the Service to HMRC.

2. What the Service does

dragonfin is an HMRC-recognised software vendor for Making Tax Digital for Income Tax Self Assessment (MTD ITSA). We provide:

• A secure conduit from your registered client device to HMRC's MTD APIs.
• OAuth authorisation flow so you can grant us permission to file on your behalf.
• Cryptographic signing of every submission so both you and HMRC can verify its origin.
• Tier-appropriate additional services (AI review for £149, human accountant review for the Human tier).

3. Your responsibilities

• Provide accurate financial data for every submission. You are legally responsible for the accuracy of everything HMRC receives with your name on it.
• Maintain valid HMRC credentials and authorise dragonfin through HMRC's OAuth flow.
• Keep your dragonfin client device secure. Your Ed25519 private key identifies your submissions — treat it like a password.
• Notify us promptly if you believe your account has been compromised.
• Pay the applicable subscription fee.

4. Our responsibilities

• Transmit your submissions to HMRC as authorised, using HMRC's approved APIs and Fraud Prevention Headers.
• Provide a receipt with a cryptographic audit hash for each submission.
• Make reasonable efforts to keep the Service available. We do not guarantee 100% uptime; MTD submissions may be delayed if HMRC's APIs are unavailable.
• Notify you promptly of any security incident affecting your account.

5. Payment and subscription

• The dragonfin app is free to install and use. Subscription fees apply only to the submission service — you pay when you file, not to hold the app.
• Subscription fees are charged annually in advance, in pounds sterling, via Stripe.
• Prices, tiers, and features are indicative at the time of publication and are subject to change. We reserve the right to modify the tiers we offer, the features included in each tier, and the price of each tier.
• Current pricing at time of publication:
  • Self — £79 per year
  • AI Assisted — £149 per year
  • Human Review — priced per-submission via marketplace bid, with a 15% platform fee and £25 minimum
• Existing paying customers are notified at least 30 days before any change to their renewal price. New prices apply only from your next renewal — no retroactive changes to a paid-up subscription period.
• If a change to tiers or features materially removes something you were paying for, you may cancel and receive a pro-rata refund of the unused period.

6. Cancellation and refunds

• You may cancel your subscription at any time. Cancellation stops future renewals. The current annual period remains active until its expiry date.
• We do not routinely provide partial-year refunds. If you cancel because the Service has failed materially (e.g. we lost HMRC vendor status), a pro-rata refund will be issued.
• New subscriptions have a 14-day statutory cancellation right under the Consumer Contracts Regulations 2013, refundable in full unless the Service has been used to submit a return during that period.

7. Suspension and termination

We may suspend or terminate your access if you:

• Fail to pay outstanding fees after two written reminders.
• Materially breach these terms.
• Use the Service in a way that risks the integrity of dragonfin or other customers (e.g. attempted abuse of HMRC's APIs).

We will give you seven days' notice and an opportunity to remedy the breach where possible.

8. Liability

• We are liable for direct losses caused by our negligence or breach of these terms, up to the total fees you have paid us in the twelve months preceding the claim.
• As a technology service provider (see §1), we are not liable for the accuracy, completeness or tax consequences of the figures and declarations you submit through the Service.
• We are not liable for HMRC penalties, interest, or investigations arising from inaccurate data you provided.
• We are not liable for HMRC's own service failures, outages, or errors on their side.
• Nothing in this section limits our liability for death, personal injury, fraud, or any other liability that cannot lawfully be excluded.

9. Data protection

Our handling of your personal data is described in the Privacy Policy, which forms part of these terms. The key commitments: we do not retain the financial content of your submissions; we do not sell data; and we do not use third-party analytics or advertising trackers.

10. Intellectual property

• dragonfin, the dragonfin brand, and the dragonfin software are owned by Dragonfire Technologies Limited.
• Content you send through the Service (your submissions, your support messages) remains yours.

11. Changes to these terms

We may update these terms from time to time. If a change materially affects your rights or obligations, we will notify you at least 30 days before it takes effect. Continued use of the Service after the change constitutes acceptance.

12. Governing law and jurisdiction

These terms are governed by the laws of England and Wales. The courts of England and Wales have exclusive jurisdiction over any dispute arising from these terms, subject to your statutory consumer rights.

13. Contact

Questions about these terms: [email protected].
For support requests, see the Support page.