Transitive phrasal verb used for completing paperwork, forms, surveys, etc.

To indicate that someone must provide missing information on an official document.

Applying for jobs, medical examinations, legal registrations, filling out tax returns.

Everyday conversation, professional settings, administrative contexts; neutral pragmatic effect in most registers.

fill out

fill out

the object to be completed (e.g., a form, questionnaire, application)

• completely
• correctly
• started to fill out

• complete the form / questionnaire (British English)
• fill in (American usage).

Using “fill out” for filling in forms when British speakers would say “fill in”; confusing with idiomatic sense ‘gain weight’. Also avoid using it as an adjective.

fill in (preferred term in UK/Canada); fill up (used for containers rather than documents).

Non‑native speakers may mistakenly use the British equivalent ‘complete’, and American learners should be aware that saying a person is ‘filled out’ can imply they have gained weight, which is not intended here.

• fill-out (rare)

In North America, especially informal contexts, ‘fill out’ exclusively refers to completing paperwork; in many Commonwealth English varieties, ‘fill in’ is preferred. The figurative sense of becoming fuller applies only metaphorically (e.g., gaining muscle mass).

Neutral – signals completion or thoroughness without implying any evaluative judgment.

“Please fill out the attached form.”

The phrasal verb 'fill out' is commonly used in American English to refer to completing a form or document. It can also be used figuratively to describe becoming fuller, such as gaining weight or muscle mass. In British English, 'fill in' is often used instead of 'fill out' for completing forms. It is important to use the correct phrasal verb depending on the context and the variety of English being used.

complete (formal)