Road Tax

[Chipchopper]

If vehicle tax runs out at the end of the month (31st), how early can I pay for it to follow on ?

[Mamyalynne]

https://www.gov.uk/vehicle-tax-advance

[Buenchico]

You can tax your vehicle from the 5th of the month online. However if you're going to be away from home (e.g. on holiday) you can tax your vehicle up to 2 months in advance by post.
https://www.gov.uk/vehicle-tax-advance

It's simplest just to pay by direct debit though:
https://www.gov.uk/government/news/vehicle-tax-direct-debit