As issuer of a voucher you are obligated to redeem it within its period of validity.
If the voucher is valid for more than 3 years, the issuer can use the voucher again for payment. If the validity period is shorter than 3 years, the issuer destroys the voucher after redemption. Due to this rule, participants of the network practically rarely receive vouchers that are about to expire.
|Validity of voucher||Action by the issuer|
|more than 3 years||must accept the voucher, can reuse it for payment|
|less than 3 years||must accept and destroy the voucher|
See also How to accept Minutos.
As a guarantor of a Minuto voucher you are only obligated to redeem it if the issuer and his legal successors (heirs) are unable to provide a service, for example in the event of: