All branches of the DVLA ( Driver and Vehicle Licensing Agency) have been closed and the head office is located in Wales, the post office does some of the applications in branch, most things like renewing your drivers license is done online, you need to input your passport details and they take your photo from there to add to your license, I am not sure what happens if you don’t have a passport, I suppose that you would have to go to the post office to fill out a form. Number plates are supplied by the dealer, there are various companies that make replacement number plates and send them by courier or you can get them at Auto Parts stores, the DVLA sends out your registration renewal form a month before it’s due and you can renew it online so long as you have valid insurance and a MOT Certificate (vehicle roadworthy), there is an option to pay for your registration renewal on a monthly direct debit basis but it costs a bit more to do this. Vehicle tax (registration fee) is charged the fuel type and the CO2 emissions the higher the emissions the higher the charge, with diesel and hybrid cars being cheaper, electric cars don’t pay tax at the moment but I suspect that will change as the Government will be loosing £40 billion pounds per year they get from, fuel tax, VAT, road tax etc, it makes up 5% of all revenue so they will have to bring in new ways of taxing vehicles or start charging us per each mile that we drive.
https://ifs.org.uk/publications/14407