SelfSubmit is designed to help you stay compliant with HMRC Making Tax Digital requirements. You remain responsible for ensuring the information you submit is accurate.

Trust

Security at SelfSubmit

We protect your account and tax records with layered authentication, monitoring, and encryption. Manage your security from Dashboard → Settings.

Account security features

The following controls are built into SelfSubmit today:

  • Strong password hashing

    Passwords are hashed by Clerk using industry-standard one-way algorithms — never stored in plain text.

  • Email verification

    New accounts must verify their email address before certain features (such as email OTP) can be enabled.

  • Password reset

    Self-service password reset is available on the sign-in page and from your account Security menu.

  • Login limits

    Sign-in API endpoints are rate-limited per IP to reduce brute-force and abuse.

  • Lockout (brute-force protection)

    After repeated failed sign-in attempts, accounts and IP addresses are temporarily locked (typically 30 minutes). This complements Clerk Attack protection — Clerk does not always show a separate “brute force” toggle.

  • Session expiry

    Idle sessions are signed out automatically after inactivity (default 30 minutes, configurable). Clerk also manages session lifetime.

  • Secure cookies

    Session cookies use HttpOnly and Secure flags in production. Application cookies (such as active business selection) use HttpOnly, SameSite=Lax, and Secure in production.

  • Two-factor authentication (2FA)

    Authenticator app (TOTP) and email OTP are enabled. SelfSubmit requires 2FA before using the dashboard and submissions.

  • Bot & attack protection

    Clerk Attack protection (bot detection) is enabled. SelfSubmit also applies its own rate limits and temporary lockouts after failed sign-in attempts.

  • Login history

    Recent successful and failed sign-in attempts are logged and visible under Settings → Login protection.

  • Device alerts

    Sign-ins from a new device or network trigger security alerts on your dashboard. Failed-attempt bursts also raise alerts.

Session inactivity defaults to 30 minutes with a 2-minute warning. Signed-in users can review login history and alerts under Settings.

Encryption & storage

  • All traffic uses HTTPS (TLS encryption in transit)
  • Sensitive tax identifiers (UTR and National Insurance number) are encrypted at the application layer before storage
  • Receipts and documents are stored in secure object storage linked to your account
  • Submission history and business records are held in a managed PostgreSQL database

Payments

Card payments are processed by Stripe. SelfSubmit does not store your full card number. Billing uses Stripe's PCI-compliant checkout and customer portal.

Infrastructure

  • Cloud application hosting with CDN and serverless infrastructure
  • Managed PostgreSQL database hosting
  • Authentication via Clerk; email via Resend; optional SMS reminders
  • Technical error monitoring and reliability diagnostics

Your responsibilities

  • Use a strong unique password and keep your authenticator app or email OTP access secure
  • If you lose your phone, use email OTP or password reset to recover access
  • Sign out on shared devices and report suspicious alerts promptly
  • Ensure figures submitted to HMRC are accurate

Report a vulnerability or incident

Security researchers: see our Responsible disclosure policy. Account concerns: email support@selfsubmit.co.uk.