I work as an accounts assistant and after work I want to help a sole trader to file her VAT return. She started trading about 3 months ago and in a few days she should receive her VAT number (invoice basis). I have all purchase invoices and receipts, but the problem is that she didn't keep the records of the CASH sales (service + materials sold). What shall I do in this situation?
-estimate sales?
-ignore it, because in the time of sale she wasn't registered for VAT?