Treth HawddTerms and Conditions
Last updated: 12 July 2026
About this service
MTD Cymraeg is a free tool that lets you prepare Making Tax Digital Income Tax Self Assessment records and submit quarterly updates to HMRC. By using this service you agree to these terms.
Who can use this service
You must be a UK taxpayer with a National Insurance number and a registered HMRC business income source to use this service to submit information to HMRC.
This is not tax advice
This service helps you record and submit information to HMRC. It does not provide accountancy, tax, or legal advice. You are responsible for making sure the figures you submit are accurate and complete. If you are unsure about your tax position, you should speak to a qualified accountant or tax adviser.
Your responsibilities
You are responsible for keeping your account password secure, for the accuracy of any data you upload or enter, and for reviewing your figures before you submit them to HMRC. Once a submission is sent to HMRC we cannot withdraw or amend it on your behalf.
Our relationship with HMRC
MTD Cymraeg is recognised by HMRC as software that can connect to their Making Tax Digital services. We are not part of HMRC, and using this service does not mean HMRC has approved or endorsed us in any other way.
Service availability
We aim to keep this service available and working correctly, but we do not guarantee it will always be available, error free, or uninterrupted. We may need to take the service offline for maintenance from time to time.
Liability
We provide this service free of charge and on an as is basis. To the extent permitted by law, we are not liable for any loss or damage arising from your use of the service, including any penalties or interest charged by HMRC as a result of information you submitted.
Ending your account
You can stop using this service and ask us to delete your account at any time. We may suspend or close an account if we reasonably believe it is being used in a way that breaches these terms or the law.
Changes to these terms
We may update these terms from time to time. If we make significant changes we will let you know, for example by email or a notice on the service.
Governing law
These terms are governed by the law of England and Wales.
Contact us
If you have any questions about these terms, contact us at support@mtdcymraeg.wales.