'Fill Out a Form' or 'Fill in a Form': Which is Correct Usage?

By Shanea Patterson, updated on November 15, 2022

Should you say ‘fill out a form’ or ‘fill in a form’? The answer can seem tricky, especially if you're learning English for the first time. But don't worry. We'll cover that below, plus teach you exactly how to use the correct phrase in a sentence.

The quick answer is that ‘fill out a form’ is generally the most common way to use the phrase in American English. In other countries, however, ‘fill in’ is completely acceptable.

The key is that if you’re going to use one, try to be consistent rather than switching back and forth between the two. 

Fill in Vs. Fill Out

So, what’s the difference between ‘fill in’ and ‘fill out’? Technically, there’s not a whole lot of difference between the phrases.

Which One is Correct – ‘Fill in a Form’ or ‘Fill Out a Form’?

Now that you know the difference between the two, which one is correct?

The short answer? Both! Just like phrases like, ‘sit in a chair/sit on a chair,’ ‘located in/located at,’ and ‘sorry for bothering you/sorry to bother you.’

‘Fill out a form’ is more commonly used in America, while ‘fill in a form’ is generally used outside of the country.

But you might also hear ‘fill in’ when talking about other things in America. For example, when taking standardized tests, they tell you to ‘fill in’ the bubbles with a number two pencil.

However, when you’re talking about forms, the general consensus is that ‘fill out a form’ is the correct usage.

Definition and Meaning

Let's quickly define both words in the phrase to better understand what it means.

Defining 'Fill'

The Merriam-Webster definition of ‘fill’ is “to put into as much as can be held or conveniently contained,” “to supply with a full complement,” “to cause to swell or billow,” “to trim (a sail) to catch the wind,” to raise the level of with fill,” “to repair the cavities of (teeth),” to stop up (obstruct),” “to stop up the interstices, crevices, or pores of (a material, such as cloth, wood, or leather) with a foreign substance,” “feed, satiate,” “satisfy, fulfill,” “make out, complete,” to draw the playing cards necessary to complete,” and “to occupy the whole of.”

It also means “to spread through,” “to make full,” “to possess and perform the duties of: hold,” “to place a person in,” “to supply as directed,” “to cover the surface of with a layer of precious metal,” “to become full.”

The noun is defined as “a full supply” and “something that fills: such as a) a material used to fill a receptacle, cavity, passage, or low place, b) a bit of instrumental music that fills the pauses between phrases (as of a vocalist or soloist), c) artificial light used in photography to reduce or eliminate shadows.”

Defining 'Form'

The definition of the word ‘form’ is “the shape and structure of something as distinguished from its material,” “a body (as of a person), especially in its external appearance or as distinguished from the face: figure,” “ beauty,” “the essential nature of a thing as distinguished from its matter,” established method of expression or proceeding: procedure according to rule or rote,” “a prescribed and set order of words: formula,” “a printed or typed document with blank spaces for insertion of required or requested information,” “manner or conduct as tested by a prescribed or accepted standard,” “manner or style of performing or accomplishing according to recognized standards of technique,” “the resting place or nest of a hare,” “a long seat: bench,” “a supporting frame model of the human figure or part (such as the torso) of the human figure usually used for displaying apparel,” and “the printing type or other matter arranged and secured in a chase ready for printing.”

It also means “one of the different modes of existence, action, or manifestation of a particular thing or substance: kind,” “a distinguishable group of organisms,” “linguistic form,” “one of the different aspects a word may take as a result of inflection or change of spelling or pronunciation,” “ a mathematical expression of a particular type,” “orderly method of arrangement (as in the presentation of ideas): manner of coordinating elements (as of an artistic production or course of reasoning).,” the past performance of a racehorse.”

Synonyms of the word include:


  • Brim
  • Heap
  • Load
  • Charge
  • Jam
  • Pack
  • Cram
  • Jam-pack
  • Stuff


  • Filler
  • Stuffing
  • Filling
  • Wadding
  • Padding

So, what does it means to ‘fill out a form’? It usually means providing personal or medical information to someone by writing it down either in print (in person) or online.

Other Common Phrases Containing the Word ‘Fill’

Take a look at some common phrases and idioms containing the word 'fill.'

  • Fill up (a cup or the gas tank)
  • Fill one’s shoes (take over someone’s job, position, or responsibilities)
  • Smoke-filled room
  • Eat one's fill (eat until you are full)

How to Use ‘Fill Out a Form’ and ‘Fill in a Form’ in a Sentence

Now that you’re well-versed in the word's definition, let’s talk about how to use it correctly in a sentence.

Take a look at a few examples of how to use ‘fill out a form’ in a sentence:

  • Donna had to fill out a form for HR when she arrived at the office.
  • We always have to fill out a form when we get to the dentist’s office.
  • We need you to fill out a form with your insurance information before your pre-op checkup.
  • I have to help my dad fill out a form for Social Security on the weekend.

If you wanted to use ‘fill in a form’ in place of these because you’re speaking to a non-English-speaking audience, feel free.

Concluding Thoughts on ‘Fill Out a Form’ and ‘Fill in a Form’

To recap, ‘fill out a form’ is the most accepted usage of the phrase in American English. Saying ‘fill in a form’ is incorrect.

Come back here if you ever need to refresh your memory. We’ve got a whole library of articles dedicated to explaining confusing words. Don’t be afraid to pop back on over and browse at your leisure.

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Written By:
Shanea Patterson
Shanea Patterson is a writer based in New York and loves writing for brands big and small. She has a master's degree in professional writing from New York University and a bachelor's degree in English from Mercy College.

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