Cookie Notice
Last updated: 8 September 2026
AimTax uses only strictly necessary cookies — the small number required for the service to work and to meet our legal obligations to HMRC. We do not use advertising, analytics, tracking, profiling or social-media cookies, and we do not sell or share any information collected through cookies.
Because every cookie we set is strictly necessary, the UK Privacy and Electronic Communications Regulations (PECR) do not require us to ask for your consent before using them, and there is no cookie banner to accept or reject. This notice explains exactly what each cookie does so you can see why it is needed.
Cookies we use
| Cookie | Purpose | Type & duration | Why it is strictly necessary |
|---|---|---|---|
| next-auth.session-token (and related next-auth CSRF / callback cookies) | Keeps you securely signed in as you move between pages, and protects sign-in forms against cross-site request forgery. | Session / short-lived. Cleared when you sign out or the session expires. | Without it you could not stay logged in, so none of the authenticated features — transactions, submissions — would work. |
| aimtax_device_id | Stores a random, one-off identifier for the device you use AimTax on. It contains no personal information and is not used to track you across other websites. | Persistent. Remains on your device so the same identifier is reused for future submissions. | HMRC requires a stable device identifier (Gov-Client-Device-ID) to be sent with every Making Tax Digital submission, as part of the fraud-prevention headers that are mandatory by law. We cannot submit your figures to HMRC without it. |
A note on similar technologies
To collect the device information HMRC requires, AimTax also reads a small amount of technical detail from your browser at the moment you submit — such as your screen size, time zone and browser type — and stores the device identifier above in your browser’s local storage as well as in a cookie, so it survives if cookies are cleared. This is used solely to build the mandatory HMRC fraud-prevention headers and for no other purpose.
We use Sentry to record technical error reports so we can fix problems. As configured, Sentry does not place advertising or tracking cookies on your device.
Managing cookies
You can delete or block cookies through your browser settings at any time. Because our cookies are strictly necessary, blocking them will stop AimTax from working correctly — you may be unable to sign in or submit to HMRC.
Guidance on managing cookies is available for Chrome, Safari, Firefox and Edge.
Changes and contact
If we introduce any new cookie that is not strictly necessary, we will update this notice and ask for your consent before it is used.
Questions about this notice can be sent to support@aimtax.co.uk. This notice forms part of our Privacy Policy.