Sign-in vs. Sign In
“Sign-in” is documented by Collins as a hyphenated noun in American English, while “sign in” is the two-word phrasal verb in Cambridge. Product-interface labels can follow house style, so the page keeps that regional/style boundary explicit.
Use “sign-in” as the hyphenated noun for an act or time of signing in in the Collins American-English entry. Use “sign in” as the phrasal verb, such as “Please sign in at reception.”
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| an act, instance, time, approval, or ending functioning as a noun | sign-in | Use “sign-in” for the documented noun use. |
| the action functioning as a verb | sign in | Use the two-word phrasal verb “sign in.” |
| a context where another documented noun spelling is explicitly established | follow the documented variant where applicable | The reviewed Collins American-English entry documents the hyphenated noun. |
Quick tests
Meaning / construction test
Is the expression functioning as a verb?
If yes: Use “sign in.”
If no: Use “sign-in” for the documented noun use.
Caveat: The reviewed Collins American-English entry documents the hyphenated noun.
Examples
Please sign in before entering the secure area.
“sign in” functions as a phrasal verb.
The sign-in took less than a minute.
“sign-in” functions as a noun.
They recorded the sign-in time in the log.
The hyphenated form functions as a noun modifier in this context.
Further guidance
Core difference
Use the documented noun or modifier form when naming a thing, result, person, or concept; use the spaced form when the words function as a verb.
Fast Test
If the expression can take ordinary verb tense or inflection in the sentence, the spaced verb form is usually the relevant choice.
Variant Boundary
Collins records the hyphenated noun “sign-in” in American English, while Cambridge records “sign in” as the phrasal verb; interface labels may still follow product house style.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- sign in — definition and meaning (opens in a new tab)Collins English Dictionary · Hyphenated sign-in noun in American English and sign in verb phrase
- sign in — English meaning (opens in a new tab)Cambridge Dictionary · Two-word phrasal verb sign in for registering arrival or entering account details