No. Are you vat registered? If you are then you claim the vat back on your old van,as you will on your new one.You don't balance one off aginst the other. If your not vat registered you will get a px allowance on your old van against your new one,which you will have too pay vat on, but can't can't claim back on either. Sometimes buying a used van is better off of someone who is a private seller and not vat registered.