If your tax is due to expire soon, the vehicle needs a valid MOT to renew it.

The MOT extensions (a 6-month extension for existing MOTs during the current lockdown) are being applied approximately 7 days before the current expiry date. You may not be able to renew the tax until this has been done if the current MOT also expires soon.

Full details about the extensions and taxing a vehicle are on the government website: Coronavirus: MOTs due from 30 March 2020