Any time or anytime — the choice looks small, but it changes how a sentence works. Both spellings are correct English, and they sound identical when spoken, which is exactly why so many writers second-guess themselves on the page. The good news is that one simple test settles the question almost every time.
Quick Answer
Use anytime (one word) as an adverb meaning “whenever,” as in “Call anytime.” Use any time (two words) as a noun phrase meaning “any amount of time” or after a preposition like at, as in “Call at any time.” If you’re ever unsure, the two-word form is always safe to use.
TL;DR
- Anytime is an adverb that means “whenever” and modifies a verb.
- Any time is a noun phrase meaning “any amount of time” or “an unspecified time.”
- Always use two words after a preposition, such as at any time.
- Both forms are grammatically correct; any time works in every context, so it’s the safer default.
- Anytime is common in casual American English but is still viewed as informal by some readers in the UK.
What “Anytime” Means and How It Works
Anytime functions as an adverb meaning “whenever” or “at any time,” and it behaves the same way any other adverb would in a sentence. For example, “Text me anytime” works the same way as “Text me later,” because anytime is describing when the action of texting can happen. Scribbr
This word also shows up as an informal adjective in certain phrases, describing something suited to no particular moment. A snack marketed for every part of the day, for instance, could be called an “anytime snack.” That usage is newer and leans casual, so it fits everyday writing better than formal documents.
One firm rule applies here: anytime cannot follow a preposition. You can’t use anytime with a preposition like at, which rules out phrases such as “at anytime.” Grammar checkers and editors flag this combination consistently because it breaks the word’s function as an adverb. Scribbr
What “Any Time” Means and How It Works
Any time, written as two separate words, works as a noun phrase. It refers to “any amount of time” and often appears inside the prepositional phrase “at any time,” which means “whenever”. Because it acts as a noun, any time can follow prepositions, sit after words like “more” or “less,” or stand as the subject of a sentence. Dictionary.com
Consider this sentence: “Do we have any time before the meeting starts?” Here, any time refers to a quantity of time, not to when an action occurs. Swapping in anytime would break the sentence, since anytime cannot describe an amount of anything.
Any time is also the correct choice in a specific idiom. When someone thanks you for a favor, the polite reply “any time” (meaning “it was no trouble”) always keeps the two words separate, since it functions as a short noun phrase rather than an adverb.
The One-Question Test That Solves It Every Time
Most confusion disappears once you apply a single substitution test. Try replacing the word or phrase with “whenever.” If the sentence still makes sense, anytime is correct. For example, “Call me anytime” becomes “Call me whenever,” which reads naturally.
Next, check whether a preposition sits right before the phrase. Words like at, for, or in signal that you need the two-word noun phrase. “We can meet at any time” cannot become “at whenever,” so the two-word spelling is required.
Finally, ask whether the phrase is describing an amount of time rather than pointing to a moment. “I don’t have any time today” is about a quantity, not a moment, so it stays as two words. This three-step check works for nearly every real-world sentence you’ll write.
Anytime or Any Time: Side-by-Side Examples
| Sentence | Correct Form | Why |
|---|---|---|
| Feel free to stop by ______. | anytime | Adverb meaning “whenever” |
| We can call at ______ of the day. | any time | Follows the preposition “at” |
| Is there ______ left before the show starts? | any time | Refers to an amount of time |
| I’ll finish this ______ soon. | anytime | Adverb modifying “finish” |
| Thanks for the ride! — ______! | any time | Fixed idiom meaning “no trouble” |
Reading across these examples shows a pattern: whenever the word stands in for “whenever,” it collapses into one word. Whenever it names a quantity or duration, it stays as two.
Formal Writing, Style Guides, and Regional Habits
Style preferences differ depending on formality and audience. In everyday American writing, anytime is widely accepted in professional emails, marketing copy, and casual correspondence. However, in more formal or academic writing on both sides of the Atlantic, many editors still prefer any time as the traditional, unmistakably correct choice.
United States: American style guides generally treat anytime as standard in conversational and business writing, though some publications still request the two-word form in formal reports.
United Kingdom: British usage has been slower to adopt the one-word spelling, and many UK style guides continue to favor any time in professional and published writing, even in adverb roles.
Because both spellings are broadly understood in the US and the UK, the safest strategy for international or mixed audiences is to default to any time whenever formality or a preposition is involved, and to reserve anytime for relaxed, conversational contexts.
Common Mistakes to Avoid
Writers most often go wrong by adding a preposition before anytime, producing errors like “at anytime” or “for anytime.” Since anytime is already an adverb, it never needs a preposition in front of it. If a preposition appears, switch to any time instead.
A second frequent mistake is using anytime as a subject or object, such as “Anytime works for me” when the intent is closer to naming a quantity (“Any amount of time works for me”). Although this particular phrase reads naturally either way, formal writing benefits from staying consistent with anytime’s adverbial role.
Finally, some writers assume anytime is simply “more modern” and always preferable. In reality, any time remains correct in every situation, even where anytime would also work. That makes the two-word form the dependable fallback whenever you’re editing quickly and don’t have time to run the substitution test.
FAQs
Both spellings exist, but they aren’t interchangeable. Anytime is one word when used as an adverb meaning “whenever.” Any time stays as two words when it functions as a noun phrase or follows a preposition.
No. “At anytime” is incorrect because anytime already functions as an adverb and doesn’t need a preposition. Use “at any time” instead.
Generally, yes. Any time reads as slightly more traditional and is a safer choice in formal writing, while anytime is common and accepted in everyday, conversational contexts.
The core grammar rule is identical in both varieties. The main difference is stylistic: British publications tend to favor any time more often in formal writing, while American writing accepts anytime more readily in business contexts.
Final Takeaway
The choice between any time or anytime comes down to one question: are you describing when something happens, or how much time something takes? Anytime handles the “whenever” role as an adverb, while any time handles amounts, prepositional phrases, and the classic “you’re welcome” reply. When a sentence feels ambiguous, defaulting to the two-word form will never be wrong, making it the most reliable habit to build into your writing.