NABL surveillance and assessment NABL Annual Surveillance 2026: How Calibration Labs Should Stay Assessment-Ready Updated: 13 September 2026 Short answer: NABL now operates a four-year accreditation cycle, but accredited laboratories still need to demonstrate continued conformity throughout that period. NABL's current assessment toolkit includes NABL 218 for Desktop Surveillance, amended on 7 January 2026, NABL 218A for Annual Surveillance, and NABL 219 for ISO/IEC 17025 assessment. The best preparation is therefore continuous evidence control, not a one-week audit cleanup. Assessment problems often begin months before an assessor arrives. An overdue calibration, an unsigned competence record, a changed spreadsheet, an unreviewed uncertainty budget or a missed proficiency-testing action may remain unnoticed until someone asks for evidence. The practical purpose of surveillance is to test whether the laboratory continues to...