Hi BURHAN SHAMURAD,
If you export goods outside of the UK then these should be at the zero rate of VAT.
Please see the guidance below:
VAT on goods exported from the UK (VAT Notice 703)
If you have been trading under the Registration threshold of VAT then there would have been no obligation to register for VAT and so your VAT registration would be voluntary.
I can only imagine that you have backdated your Registration date and so HMRC are looking to collect the VAT which should have been charged from this date.
I would recommend you check this date on your VAT Certificate.
If the date is incorrect then you could request for this to be changed by writing to the following address:
BT VAT
HMRC
BX9 1WR.
If you find that the date of your Registration is correct then please contact our Helpline so that we can look in to your account for
you.
VAT: general enquiries
Thank you.