Why are many recruiters suspicious of functional resumes?

Because functional resumes separate skills from the jobs where you used them, recruiters cannot easily check when, where and how long you used each skill. That makes the resume hard to verify and can look like an attempt to hide something.

Common concerns:

• Employment gaps or short jobs being hidden.
• Skills that may come from long ago or from minor tasks.
• No clear sense of career progression or level.
• Extra effort needed to match skills to roles.

There is no single rule all recruiters follow, but these concerns are widely reported. If you have something to explain, such as a gap or a career change, a hybrid resume with honest dates and a short explanation usually earns more trust than a functional one.