#1. Tier 1 — Authority classification
Dubai Municipality contractor classification (unlimited or G+x), DDA and Trakhees registrations where the plot demands them, Civil Defence approval for controlled demolition. Verifiable directly with the issuer.
#2. Tier 2 — ISO trio
ISO 9001 (Quality), 14001 (Environmental), 45001 (HSE). Check expiry date and issuing body — UKAS, ANAB, DAC-accredited bodies count, mill-certificate-only does not.
#3. Tier 3 — Personal competence
IOSH Managing Safely or NEBOSH IGC for site managers, confined-space and working-at-height tickets for crews, controlled-demolition certification for blasting supervisors.
#4. What to ignore
Generic 'membership' badges, unverified award icons, and certificates from training providers without third-party accreditation. They pad a profile but prove nothing.
#5. USF certification stack
DM, DDA and Trakhees approved; ISO 9001/14001/45001 (UKAS); senior staff NEBOSH IGC; crew confined-space and working-at-height current. All evidence shared on request.