May I use customer photos in my portfolio?

Customer photos in your portfolio = commercial use = dual legal regime. Portrait law (Dutch Copyright Act Art. 19-20): for commissioned photos (e.g. photographer makes portrait for client) client has exclusive publication right. You may not publish without client consent. GDPR: photo = personal data = separate basis required (Art. 6 — usually consent Art. 7). What do you need? Model contract with: (a) explicit consent for portfolio use, (b) channel specification (website, Instagram, presentation, yearbook), (c) duration (5 years standard, renewable), (d) revoke procedure, (e) possible compensation. Best practice: consent UP FRONT in booking flow. NOT asked after ("nice photo, OK for Insta?") — then consent usually not "free" because client feels obligated. On refusal or revoke: remove within reasonable time — otherwise portrait-right claim + GDPR Art. 17. For B2B portfolio (corporate event, company outing): company consent is not the same as employee consent. Ask per person. Templates: DuPho (Dutch professional photographers) has model contracts free.