Schema versions

Supported ISO 20022 versions and per-message schema selection.

Which version a bank requires varies by bank and by regulatory cut-over, so it is a per-message choice rather than a compile-time constant.

The version is not the scheme. These are two independent axes and it is worth keeping them apart: all three credit-transfer schemes — SCT, SCT Instant and OCT Inst — use pain.001.001.09 in the supported current profiles. Pick the version with Pain001Builder::schema and the scheme with CreditTransferGroup::kind; see credit transfers. The one interaction is that OCT Inst postdates the older schemas, so EOLO requires pain.001.001.09.

Readers require the exact supported message namespace and envelope. The reader contract distinguishes accepted versions from versions covered by pinned XSD fixtures; neither implies full inbound XSD validation.

Selecting one🔗

Both builder enums parse from the message identifier and the namespace URN, so the target can come from configuration rather than a recompile:

use sepa::Pain008Builder;
use sepa::pain008::DirectDebitSchema;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let schema: DirectDebitSchema = "pain.008.001.02".parse()?;
    let builder = Pain008Builder::new("Stadtwerke GmbH", "DD-2026-07-001").schema(schema);

    assert_eq!(schema.message_id(), "pain.008.001.02");
    assert_eq!(builder.group_count(), 0);
    Ok(())
}

The versions differ on the wire, not just in the namespace, and the crate handles the differences rather than papering over them: BIC was renamed BICFI in the 2019 maintenance release, ReqdExctnDt became a date-time choice, and the SMNDA marker sits in a different element in the legacy German schema. Where a feature genuinely does not exist in a version — an instant transfer on a schema with no local-instrument element — you get a typed error instead of a file that fails its own schema.

Why not newer ISO versions?🔗

ISO advises communities to use the most recent message definition available, and has published pain.001.001.13, pain.008.001.12 and pain.002.001.15.

Use the version required by the applicable scheme profile and your bank. A newer ISO version is not automatically an accepted SEPA version.

Those versions have been mandatory since 19 November 2023. ISO’s guidance is written for communities free to choose their own version; a scheme participant is not one.

Address requirements are independent of message-version selection; see postal addresses. Proposals for future versions do not change the versions accepted by the current profiles.

How the output is checked🔗

CI validates generated fixtures for each emitted schema version against pinned ISO XSDs, plus German GBIC subsets for the default SCT/SDD versions. Builders validate field rules; they do not run an XSD validator for each output. Schema validity is test evidence, not a guarantee of bank acceptance.

Full API reference on docs.rs. Found a mistake? Open an issue.