The possible values for paymentType attribute are:

DescriptionValue
The merchant receives an order he is able to fulfil in a single shipment.ONE_OFF
The merchant establishes an agreement with the buyer to pay for goods or services in multiple transactions over an agreed period.
The merchant requests Monext to process the installments.
MX_INSTALLMENT
These are payments for the delivery of ongoing goods or services. They have a fixed interval and fixed amount for each payment.
The merchant requests Monext to process the installments.
MX_RECURRING
The merchant checks validity of PAN and expiry date using an Account Verification transaction.
There are many situations in wich a merchant may need to know if a card is valid, stolen, expired or frozen before initiating a transaction.
ACCOUNT_VERIFICATION
These are payments for the delivery of ongoing goods or services. They have a fixed interval and fixed amount for each payment.
The merchant processes the installments.
RECURRING
The merchant establishes an agreement with the buyer to pay for goods or servces in multiple transactions over an agreed period.
The merchant processes the installments.
INSTALLMENT
A merchant initiates a payment on shipping with the order shipment beyond the authorisation release period or the merchant establishes an agreement with the buyer to ship goods at a later time.PRE_ORDER
The merchant establishes an agreement with the buyer to charge him based on his consumption.UNSCHEDULED
A merchant initiates an authorisation request for the rental of a good or service.RENTAL_SERVICES_PAYMENT
This payment case applies to a merchant from whom a buyer has ordered and consumed a rental of goods and services that results in additional charges after the payment file has been closed.DELAYED_CHARGE
This payment case applies to a merchant from whom a buyer has booked a rental of goods and services and does not show up with a contractual commitment.NO_SHOW
This function is used to refund the buyer if the merchant has not retained the authorisation transaction ID required for the doRefund function.CREDIT
Decoupled payment across multiple merchantsMULTIPLE_MERCHANTS
Bank TransferBANK_TRANSFER