Output tax must be accounted for when payment is received.
Cheque
They are treated as received on the date the cheque is received or if later the date on the cheque. If the cheque is not honoured an adjustment can be made.
Credit/debit card
They are treated as received/paid on the date of the sales voucher.
Standing order/direct debits
They are treated as received/paid on the day the bank account is credited.
Part payments
VAT must be accounted for on all receipts/payments even where they are part payments. Part payments are allocated to invoices in date order (earliest first) and any part payment of an invoice allocated to VAT by making a fair and reasonable apportionment.
Records
In the cash accounting scheme the prime record will be a cash book summarising all payments made and received with a separate column for VAT. The payments need to be clearly cross-referenced to the appropriate purchase/sales invoice. Additionally, the normal requirements regarding copies of VAT invoices and evidence of input tax apply.