The Paymash voucher function is used to create value vouchers. Such a voucher is to be treated as a means of payment. The service to be received is not defined. Only at the time of redemption is the service relevant to turnover and therefore taxable at the applicable tax rate. The value of the service rendered (or the object sold) is considered to be the service.
This booking example is a voucher with a value of 100.00
A customer buys a voucher from you worth 100.00
He pays for the voucher with his credit card.
Your customer pays with a voucher worth 100.00
In short, it is only when the voucher is redeemed that it becomes relevant to sales and is booked accordingly by Paymash.