Does one fill out a form or does one fill in a form? I've gotten different answers from the people I've asked.

Google search results:

  • fill in a form — 14,200,000
  • fill out a form — 7,000,000
  • 1
    To me as a German this is very interesting. Seems to me that there must have been some strong influence of German speakers in forming American English. In German you would lterally "fill out" a form ("ein Formular ausfüllen"). So that might explain the difference between British and American English. – user15507 Dec 2 '11 at 14:14
  • Someone in EL&U recently wrote "fill up a form" and then I knew he wasn't an American. From "fill out" or "fill in" I would not draw that conclusion. – GEdgar Mar 9 '12 at 13:47
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    related – New Alexandria Oct 24 '12 at 16:52
  • @GEdgar, is "fill up" grammatical then? – Pacerier Mar 26 '14 at 12:56
  • Yes, it is grammatical. Grammar (in general) does not depend on the meanings of the words. If "fill up a bottle" is grammatical, then so is "fill up a form". – GEdgar Mar 26 '14 at 12:59

It appears that this is a British/American distinction. The Corpus of Contemporary American English (COCA) reports 92 incidences of “fill out a/the/this form” and just 2 of “fill in a/the/this form”, clearly establishing “fill out” as the standard idiom in American English. I haven’t worked out how to search the British National Corpus yet, but I wouldn’t be surprised if the results were reversed there.


OK, I got the BNC to respond to queries—although it sure takes its sweet time—and I got 19+7=26 results for “fill in a/the form”, and 5+1=6 for “fill out a/the form”. So it does appear that British English favors fill in over fill out, although not to the degree to which American English favors fill out over fill in.

  • I suspect that, as with most things, influence of American media has driven prevalance in British speech in recent years; Stephen Fry and Hugh Laurie have a sketch in their sketch comedy show A Bit of Fry & Laurie from about 1987 in which Fry is corrected by Laurie for asking him to "fill out a form". – Myles Jan 30 at 17:40

Both are perfectly acceptable.


As an Englishman living in the US for almost 20 years, "fill out" still sounds jarring to my ears. I had never heard it used before I came to America.

I rarely hear "fill in" on this side of the Atlantic.


In my dialect of American English, you "fill out the form" by "filling in the blanks" on the form.

P.S. to fill out the form is to complete it. To fill in the form is to supply information as required.

  • But doesn't filling in a form necessarily mean completing it? – Mari-Lou A Jan 16 '18 at 20:56
  • @Mari-Lou: I am referring to an aspectual difference when out is used in conjunction with the verb. – TRomano Jan 16 '18 at 21:16
  • If someone asks me to fill in the missing details of the story, it must also mean to tell the whole story, to "fill in" the missing particulars in order to get the whole picture. – Mari-Lou A Jan 16 '18 at 21:38
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    aspectual, Mari-Lou. – TRomano Jan 16 '18 at 21:55
  • 1
    "with forked tongue". – TRomano Jan 16 '18 at 22:00

The Americanism follows in line with other usages:

  • Knock out (to complete, slang, verb)
  • Round out (add more in order to ensure a broad range, slang)
  • fill out (no form-based, as in "why don't you use the rest of those flowers to fill out this basket")

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