SEPA SDD is the direct-debit counterpart to SCT. The creditor pulls funds from the debtor's account under a pre-signed mandate. Two variants: CORE (the consumer-facing default with an 8-week unauthorised-refund window) and B2B (corporate-to-corporate with no refund window once collected).
The carrier message is pain.008. Required fields: a mandate identifier (MndtId), the date the mandate was signed (DtOfSgntr), the sequence type (FRST for first collection, RCUR for recurring, OOFF for one-off, FNAL for final), and a creditor scheme identifier (assigned by the creditor's bank).
Critical lead-times: CORE FRST requires presentment at least 5 banking days before collection date; CORE RCUR / FNAL requires 2; B2B variants are 1 day. Missing the lead-time results in an immediate scheme reject.
iso-compliant emits SDD via POST /v1/iso20022/pain.008 with mandate validation, sequence-type grouping (FRST and RCUR transactions must live in separate <PmtInf> blocks under SEPA rules), and CORE/B2B variant selection.