The law used to be that you had until the
fifth working day of the expiry month to fit a new disc and the specific offence was failure to
display a current road fund licence.
It's recently changed and not displaying one is not an offence in itself, the offence is now failing to
own a current road fund licence, (this takes into consideration that most discs are now purchased online and some do have problems with reciept of their new discs).
A roadside check would be carried out and if it is found that one has not been
paid for before the expiry of the old disc then an offence has been committed but if it has been paid for but not displayed due to non receipt you will be ok.
If the Dealer can prove that a new disc has been paid for but not received by them yet then you can drive your car upto and including the 7th of this month without a new disc being displayed.
If the Dealer can not or will not confirm that they have paid for the disc then
DO NOT DRIVE YOUR CAR as you will be reported to DVLA, recieve a PCN for £80 and possibly end up with a DVLA fine of up to £1000.
Originally taken from DirectGov-
If you prefer to tax in the last few days of the month, there is now an exemption from the offence of not displaying a tax disc. This exemption covers the first five working days of the month and allows time for the new disc to arrive in the post.
Originally taken from Department of Transport-
The first of the changes has come about because DVLA has found that towards the end of the month, many motorists taxing their vehicle online or by phone do not complete the transaction when they realise that their tax disc may not be received in time for the 1st of the following month. As a result,
from the 1st of September 2008, those buying their vehicle tax online, by phone or by post will be able to legally continue to drive their vehicles for up to 5 days while they wait for their new tax disc to arrive. This will only apply where the new tax disc has been applied for before the current one expires and motorists should continue to display the expired disc on their vehicle, until the new one arrives. This will be of great benefit to those motorists who have to leave buying their tax disc until the last day of the month, because they are waiting to be paid. They can now still do that, but also get the benefits of taxing online, by phone or by post.
I personally would kick off with the Dealer.
Have you received or do you need a current MOT certificate?
If so you could do this-
Taxing your vehicle without a V11 (tax reminder) or a Current V5C (vehicle registration certificate)- A completed V10 ‘Application for a tax disc'
- A completed V62 ‘Application for a Vehicle Registration Certificate V5C’, if you don’t have a registration certificate
- An MOT test certificate (if your car or motorcycle is over three years old)
- Insurance that offers at least third party cover
- The payment for vehicle tax (unless your car is exempt from paying vehicle tax)
As soon as you do this in a Post Office then you should recievea tax disc and can be on your way.