Custom Form Validation in CF7 Addons — a practical guide to Contact Form 7 addon validation with clear examples you can reuse in real projects.
Contact Form 7 Tutorial Series (87/100). Prefer one article? Read the complete Contact Form 7 tutorial.
Short description
Invalidate with clear messages; don’t rely only on client-side checks.
Validation tip
Use wpcf7_validate_{type} filters
Return $result unchanged when OK
Invalidate with user-safe messages