What certifications don't expire?

A minority of certifications never expire: most academic degrees and diplomas, some foundational IT certificates (like CompTIA's older lifetime certs, or vendor badges issued before recertification policies), and various one-off training certificates where the issuer chose not to require renewal.

The overwhelming majority do expire or require maintenance: professional licenses (medical, legal, trades, finance), safety certifications (first aid, forklift, food handling), quality and security standards (ISO 9001, ISO 27001, SOC 2 reports age out), IT certifications (AWS, Cisco, PMP all recertify every 2–3 years), and every SSL/TLS certificate.

Treat 'does it expire?' as a question to verify per certificate, not assume. Issuers change their policies. For everything with a date, what matters is capturing that date the day the certificate arrives, while the paperwork is in your hand.