5 Common PHP Form Bugs That Break POST Submissions and How to Fix Them

PHP forms that appear broken are almost always caused by a small disconnect between HTML markup and the server-side script reading it, not a flaw in PHP itself. The five most frequent culprits are a missing or incorrect method attribute on the form tag, mismatched input name attributes and $_POST keys, case-sensitive key errors in isset() checks, a form that never actually submits, and HTML output sent before a header() redirect call. PHP populates $_POST or $_GET based solely on an input's name attribute, meaning id values and label text are irrelevant to data retrieval. Developers can use $_REQUEST temporarily during debugging to confirm data is reaching the script before narrowing down the method. Working through these five issues in order typically resolves most PHP form submission problems within minutes.