Charging backdated VAT

Ive recently started delivering parcels for a national courier company on a self employed basis. I have just registered for VAT on the flat rate scheme and am wondering if I can charge a backdated VAT only invoice to the company i work for (I started working for them just over three months ago). Thanks.

Hi,
You can go back to your customer and charge VAT, however if the service has already bee supplied and you charged them a net  feen then they are under no obligation to pay it.
If you had to invoice your customer while you were waiting for your VAT number to be processed then the folloeing guidance explains that procedure:
Accounting for VAT
Thank you.