Vat on carriage

Hello

I have been with my accountant for 7 years.

I have an Internet business where I sell through Amazon and E Bay.

VAT is charged on the selling price of each item. I have not been charging VAT on the carriage.

I recently had a routine VAT inspection where the inspector informed me that VAT should be charged
On carriage.

My accountants know my business and prepare my accounts every year, on no occasion have they mentioned
that I should be charging VAT on carriage.

Are my accountants at fault in not informing me of this and should they bare the costs in this investigation?

Regards

Michael Keen