The deadline for filing the annual tax return is 31 January. Everyone knows that - after all, that's the month all the reminder adverts start appearing in the media. However, the 31 January deadline only applies to returns that are submitted electronically. Unlike companies, individuals can still fill in a paper return and submit it to HMRC. The only problem is that the corresponding deadline is three months earlier, i.e. 31 October. If this is missed, a £100 penalty will be applied. Of course, this can be avoided by submitting an electronic return before 31 January, but for some people this isn't practical. For example, they may not have access to a computer.

In some circumstances, a return is incapable of being accepted  electronically due to HMRC's system. In these instances a paper return is the only option, and an extended deadline of 31 January applies. A late filing penalty would initially be charged, but known issues will be accepted as a reasonable excuse upon appeal. A list of current issues is availaible for 2020/21.