An authorisation is a set-up that is required to allow you to e-file your MTDVAT returns to HMRC through any third party software. To get an authorisation, you will need to go through the "two step verification process". This is an extra security measure put in place by HMRC to ensure the secure exchange of data. By completing this process, you will authorise our request to receive and send HMRC your MTDVAT on your behalf. The authorisation will expire every 18 months. The authorisation process should be repeated.