Why can't I renew my car tax on line? My current car tax and insurance both expire on 31st July. I renewed my insurance on 13th July and received the certificate a couple of days later. The insurers assure me that the DVLA database was updated on the same day as the certificate was issued. Despite this the DVLA site tells me that it has no record of insurance for my car so can't renew the licence. It says that this may occur because the renewed tax and insurance start on the same day. I have to go to a post office. What a shambles. there must be millions of vehicles in the UK that have the tax and insurance valid from the same day. It is also worthwhile to note that though the DVLA pays the Post Offices a commission on car tax they collect, there is no discount when the "middle man" is cut out of the deal.