Incorrectly Invoiced VAT.

saajan_12

kevcl15 said:

Original amount was £1,117.51. Invoice quoted the VAT at 5% - £55.88, total amount for the service - £1173.39, all paid once the connection was made.

What they are saying is the connection type was wrongly classified and doesn't meet the requirements for VAT at 5%, should have been 20%; from their e-mail....
"Where we have charged at 5%, we should have charged at 20% as the connections were granny annex (which is exempt for a 5% charge). "

Still say this is their error and I have fulfilled my part of the contract by paying the invoice in full as agreed when the contract was entered into.

Please clarify what happened chronologically. So
1. Quote of £xx received - what was the amount there, was it inclusive or exclusive or vat?
2. Go ahead to do the work
3. Work done
4. Invoice for £xx raised
5. Invoice paid

OR was the invoice before the work was done? ie 
1. Quote of £xx received - what was the amount there, was it inclusive or exclusive or vat?
2. Go ahead to do the work
3. Invoice raised for £xx 
4. Work done
5. Invoice paid

Thsi will be crucial on who is right.