The self-assessment tax line usually follows the process outlined in the image below, with 31st July signalling the last day you can make your second payment on account before interest would be charged.
However, due to COVID-19, the 2nd payment on account can now be deferred till 31/01/2021. This means that the amount needs to be paid sometime between now and the end of January, when you will be making the outstanding payment for your 19/20 tax return (if applicable), along with the first payment on account towards your 20/21 tax return.
You can choose to make the payment as normal if you want to but if you choose to to make the payment(s) over time, there is nothing you need to do. HMRC has just extended the deadline and there is no need to call them or tell us. If you have any questions please don’t hesitate to contact our expert tax agents on 020 8761 8000.