vat clawback ?

Hi people,
Another one on vat.
We are in a subsection of the construction industry for 5 years and are having a tough year so far same as everyone else. From a cashflow pint of view vat is an issue as buy in the north ex vat a lot of our products. Because of the two thirds rule we had been charging vat at 21%. I have since spoken to others in the industry and it seems I am the only one of about 25 business that I know of paying 21%. I tried to get our accountant to check it out but he seems more interested in telling us what we cant do but to be fair he keeps us on the straight and narrow all the same.
By setting up a workshop these business have been charging 13.5%. My question is twofold as we now have done the same would revenue start taking a keener interest in us if we start making a return at 13.5% and is there anyway we can claw back the vat we had been paying at 21%?
Opnions and advise appreciated.

The issue here is were you correctly charging the standard rate or not. If you were supposed to charge the standard rate ( regardless of what others may have been doing ) and were charging the standard rate then there is no issue. If, as a result of changes in your business you are now entitled to charge the lower rate, then Revenue would have no problem with that. If you are doing what is correct, then you have nothing to fear from Revenue.

If, through error, you have been remitting VAT at a higher rate than you should have, then you need to (a) establish that you have in fact been overpaying and (b) get your accountant to see what overpayment (if any) would have arisen. Bear in mind the 4 year rule which restricts taxpayers to the current + past 4 years on reviews.