Cookie Policy
Last updated: 20 April 2026
1. What Are Cookies
Cookies are small text files stored on your device when you visit a website. They help us provide a secure and functional experience.
2. Cookies We Use
Essential Cookies (Always Active)
| Cookie | Purpose | Duration |
|---|---|---|
| Session cookie | Authenticates your login session | Browser session |
| CSRF token | Protects against cross-site request forgery | Browser session |
| Cookie consent | Remembers your cookie preferences | 1 year |
hmrc_device_id | Stable device identifier required by HMRC's Making Tax Digital Transaction Risking specification. Contains no personal data. | 5 years |
hmrc_fingerprint | Captures browser metadata (screen size, timezone, plug-ins) required by HMRC fraud prevention rules. Sent only to HMRC during tax submissions. | 30 days |
These cookies are strictly necessary for the service to function or are legally required. They cannot be disabled while using TaxMTD.
Functional Cookies
| Cookie | Purpose | Duration |
|---|---|---|
| Theme preference | Remembers dark/light mode | 1 year |
| Sidebar state | Remembers navigation preferences | 1 year |
| Table preferences | Remembers column sizes, sorting | 1 year |
| Date range | Remembers selected date filters | 30 days |
| Active entity | Remembers the business entity you last selected | 1 year |
3. Third-Party Cookies
We do not use:
- Advertising or tracking cookies
- Google Analytics
- Facebook Pixel
- Any social media tracking
3.1 Plaid Link
When you connect a bank account, Plaid Link is loaded from Plaid's CDN. Plaid may set its own cookies strictly for the duration of the bank-connection flow. See Plaid's End User Privacy Policy for details. These cookies are scoped to Plaid's domain, not TaxMTD.
4. HMRC Fraud Prevention
Two cookies (hmrc_device_id and hmrc_fingerprint) are set specifically to comply with HMRC's Making Tax Digital Transaction Risking specification. HMRC legally requires us to transmit a consistent device fingerprint with every tax submission. These cookies are used only to generate the HMRC Gov-Client-* headers at submission time - we do not read them for any other purpose, and the data is never shared with third parties other than HMRC. See our Privacy Policy Section 2.4 for the full list of data transmitted.
5. Managing Cookies
You can delete cookies through your browser settings at any time. Blocking essential cookies may prevent you from using the service. Blocking the HMRC cookies will prevent you from submitting tax returns.
6. Changes to This Policy
We may update this policy from time to time. Changes will be posted on this page with an updated date.
7. Contact
For questions about our cookie policy, contact us at support@taxmtd.uk.