Self Assessment deadline passes - What now?

October 31st was the last day for taxpayers to return the Self Assessment form.

Those who wished to complete their Self Assessment on paper were required to return the form by 31 October. The only exception to this is cases in which the taxpayer did not receive their notice to file until after 31 July. In these cases the deadline is three months after receipt of the notice.

Taxpayers who missed the paper deadline still have time to complete their Self Assessment online – but it is important that first-time online users take action now to ensure that they do not incur a penalty.

In order to file a Self Assessment online, taxpayers must first register for HMRC’s online system. This can take around 10 days, and it is therefore vital that you do not leave this until the last minute.


You can sign up for the online service using the step-by-step wizard on the HMRC website. To begin with you will require your Unique Taxpayer Reference, which you will have been assigned when you registered as self employed. You will be able to find this on your notice to file, or on your paper Self Assessment form. You will also need either your National Insurance number or your post code.

You will then need to provide HMRC with a few details about yourself, including your name and email address, and create a password. The system will then assign you a user ID, which you should keep in a safe place; you will require this in order to log in to your account.

At the end of the sign-up process, HMRC will send you an activation PIN by post. This can take around a week to arrive. You will receive one PIN for each government service you sign up to – for example, if you also sign up to use the VAT return service, you will receive a separate activation PIN for this.

Once you receive your PIN you will need to use it within 28 days of the date on the letter. If you fail to do so you will have to repeat the process.

Remember: the deadline for the online submission of your Self Assessment tax return is 31 January. If you miss this deadline you will have to pay a penalty.