SignRequest currently offers three payment methods: credit card, SEPA mandate (Europe only) and wire transfer (yearly subscriptions only).
A SEPA mandate is a direct debit from banks that support the 'Single Euro Payments Area', which is mainly Europe only. -> Countries a part of SEPA
The maximum SEPA mandate can be €1000. Anything above this will need to be charged by either Credit Card or Wire transfer (yearly subscriptions only). Minimum wire transfer is $1000 or €1000.