Comment by whylo

DVLA systems seem to be an absolute mess, and many public-facing systems are still using the DirectGov styling (which was replaced by GOV.UK in 2012). A lot of their services are completely unavailable overnight from 7pm-7am. So if you sell a vehicle on the last day of the month and go to register the sale after 7pm, bad luck - you're getting charged another month of vehicle tax.