The coexistence period between legacy MT and ISO 20022 (MX/pacs) messages for cross-border FI-to-FI payment instructions ended on November 22, 2025 - the single most consequential infrastructure change in cross-border payments in decades.
What Changed
MT 103, MT 202, MT 200, and MT 205 sent after this date are automatically routed through contingency processing with limited conversion to ISO 20022. MT 102, MT 102 STP, MT 103 REMIT, MT 201, and MT 203 are immediately rejected (NAK'd) and will not be delivered. By November 25, 97% of payment instructions were being sent natively in ISO 20022 format.
Financial Consequences
From January 1, 2026, SWIFT applies surcharges for contingency processing of MT payment instructions and for in-flow translation services. Charges are volume-based and not included in Fixed fee or Swift Essentials packages. Any institution still sending legacy MT formats is now paying premium rates on a degraded processing path.
What This Means
Banks that delayed migration are now on a chargeable fallback path with reduced data richness. The adoption gap was dramatic - as late as December 2024, only 32.9% of organizations had adopted ISO 20022 natively, yet by coexistence end, 97% of payment instructions were compliant. This concentration of last-minute migration created significant operational risk during the transition.
Source: SWIFT