The European Central Bank has published an updated BPM6 booklet setting out detailed operational requirements for transmitting monthly and quarterly balance of payments (b.o.p.) statistics, international investment position (i.i.p.) and international reserves template data within the European System of Central Banks (ESCB), alongside monthly reporting on cross-border euro banknote shipments. The booklet replaces the prior version and applies to data transmission for the 21 euro area countries, as applicable from 16 March 2026. Key updates include switching geographical references from I9/J9 to I10/J10 to reflect the euro area’s new composition from 1 January 2026, and revising compliance guidance following the replacement of legacy sign validations with SIGN_ERROR and SIGN_WARNING (SIGN_WARNING breaches do not constitute non-compliance, while SIGN_ERROR breaches do). The booklet restates timeliness expectations (by 14:00 CET) of T+44 calendar days for monthly b.o.p., T+82 for quarterly b.o.p./i.i.p., T+10 for the monthly reserves template and T+35 for banknote shipment data, and describes transmission via ESCB XML Data Integration (EXDI) using SDMX-ML (Compact 2.0 or Structure-specific 2.1). It also reiterates the requirement to submit qualitative metadata on major events, significant revisions and net errors and omissions adjustments, with an indicative reporting threshold of EUR 3 billion, and adds new content including reporting treatment for ECB supervisory fees and sanctions, a mapping between payment statistics merchant category codes and b.o.p. categories, and new appendices covering reserve assets “community concept” compilation for euro area joiners and SEFER counterpart areas.