Startup vs. Start-up vs. Start Up
Cambridge records “start-up” with “startup” as an alternative noun/adjective form for a newly started business or related context. “Start up” is the two-word phrasal verb for beginning operation or starting a business, organization, vehicle, or engine.
Use “start up” for the verb. For the noun/adjective, both “start-up” and “startup” are documented.
Key details
Choose the right form
| Grammatical role | Use | Decision |
|---|---|---|
| verb: begin operating or cause to begin | start up | Keep the phrasal verb as two words. |
| noun/adjective for a newly started business or related context | start-up | Documented non-verb spelling. |
| same noun/adjective role | startup | Also documented; house style can choose between the two non-verb forms. |
Quick tests
Part-of-speech test
Can the expression change to “started up” or “starting up” in this sentence?
If yes: Use the two-word verb “start up.”
If no: If it functions as a noun or adjective, “start-up” and “startup” are both documented.
Caveat: The non-verb spelling is a style choice between documented variants; do not turn that choice into a universal correctness rule.
Examples
Please start up the system before the meeting.
“Start up” is the two-word phrasal verb.
The start-up hired its first employee.
“Start-up” is a documented noun spelling.
The startup team revised its launch plan.
“Startup” is also a documented noun/adjective form.
Further guidance
Core difference
Use two words for the action “start up”; use “start-up” or “startup” when the expression functions as a noun or adjective.
Fast Test
If it becomes “started up” or “starting up,” it is the two-word verb.
Variant Boundary
Cambridge explicitly records “start-up” and “startup” as alternatives, so house style can govern the non-verb spelling.
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.
- START (SOMETHING) UP — English meaning (opens in a new tab)Cambridge Dictionary · Phrasal verb “start up” plus noun/adjective “start-up” and “startup” variant