There are two kinds of SEPA direct debits (Lastschrift):
- SEPA Core Direct Debit
- SEPA Business to Business Direct Debit
(source:
https://de.wikipedia.org/wiki/Lastschrift#Arten_der_SEPA-Las...)
Only the first one is used when you buy things in the internet (the second one is only important for B2B transactions). It can be reversed without giving any reasons for 8 weeks. If you have not authorized (in other words: it was fraudulent) even for 13 weeks. If you reverse it, though it was legal, it's the vendor that has the problem (and has to collect the money). That's why often only larger vendors will accept SEPA direct debit (small vendors will often insist that you use SEPA credit transfer instead that is a lot less customer-friendly in case of a fraudulent vendor). SEPA credit transfer is in my opinion not suitable for "fast, spontanous" payments, though, for reasons I won't explain here.