can checkin (check in)

Use check in (two words) for the verb: someone performs the action. Use check-in (hyphen) for the noun or adjective that names or describes a thing. Checkin (one word) is nonstandard and looks like a typo in most contexts.

Quick answer

Verb = two words: check in. Noun/adjective = hyphen: check-in. Avoid checkin (one word).

Action? Use two words: I need to check in at 3 PM.
Label or modifier? Use a hyphen: the check-in desk, check-in time.
If you find checkin, change it to check in or check-in based on context.

Core rule - action vs thing (fast)

Ask whether the phrase names an action or a thing. If it's doing something, keep the verb and particle separate: check in. If it names, labels, or modifies a noun, hyphenate: check-in.

Verb (action) → check in (two words).
Noun/adjective (thing or modifier) → check-in (hyphen).
One word (checkin) is usually wrong in formal writing.

Wrong: Can you checkin when you arrive?
Right: Can you check in when you arrive?
Wrong: The checkin closed at noon.
Right: The check-in closed at noon.

Hyphenation, spacing, and grammar

Hyphenate when the phrase appears before a noun as a compound modifier (check-in desk). Keep two words when the phrase is the verb or follows the verb. Treat check in as a phrasal verb: the particle in stays connected in meaning, not merged into a single word.

Before a noun = hyphen: the check-in desk, check-in policy.
After a verb or alone = two words: We will check in at noon. I checked in already.
Conjugation: check in / checks in, checked in, checking in, have checked in.

Wrong: Please wait at the check in desk.
Right: Please wait at the check-in desk.
Wrong: I will check-in after my call.
Right: I will check in after my call.
Wrong: They have checkin already.
Right: They have checked in already.

Real usage and tone - work, school, casual

Context affects tone but not the basic rule. Corporate and formal writing often uses the noun form for processes; speech and chat tend to use the verb form. Below are natural examples for each setting.

Work - The check-in process for contractors starts at 8:30 AM.
Work - Please check in with your manager before you begin the task.
Work - Email me your check-in time so we can schedule equipment.
School - Students must check in at reception before class.
School - The check-in sheet is pinned to the door each morning.
School - Have you checked in for the exam yet?
Casual - I'll check in when I land; give me a heads-up if plans change.
Casual - Text to check in later tonight; I might run late.
Casual - Let's check in at the café before the movie.

Try your sentence

Test the whole sentence. Swap in register or report to see whether you need the verb or a noun.

Examples gallery - common mistakes and quick rewrites

Copy these direct replacements. When a tone improvement helps, use the suggested rewrite.

Wrong: Can you checkin at reception before the meeting?
Right: Can you check in at reception before the meeting?
Wrong: Our checkin opens at 7:00 a.m.
Right: Our check-in opens at 7:00 a.m.
Wrong: Please checkin online before arriving.
Right: Please check in online before arriving.
Wrong: I will check-in with you tomorrow.
Right: I will check in with you tomorrow.
Wrong: The checkin counter is to your left.
Right: The check-in counter is to your left.
Wrong: We need to checkin the guests by 6 p.m.
Right: We need to check in the guests by 6 p.m.
Rewrite:
Wrong: "Can you check in when you arrive?" → Better: "Please check in at the front desk upon arrival."
Rewrite:
Wrong: "The check-in is at 2." → Better: "Check-in begins at 2:00 PM at the main desk."
Rewrite:
Wrong: "I'll checkin later." → Better: "I'll check in with you later this afternoon."

Rewrite help - quick 3-step fix and examples

Three steps to decide and correct:

Step 1: Replace with register or report. If that fits as an action, use check in.
Step 2: If the phrase labels a desk/time/policy before a noun, hyphenate: check-in.
Step 3: If you find checkin, update it and re-read the sentence.

Wrong: We ask all volunteers to checkin before the event.Fix: We ask all volunteers to check in before the event. (or "register before the event")
Wrong: The checkin procedure is in the manual.Fix: The check-in procedure is in the manual.
Wrong: Subject: Checkin ReminderFix: Subject: Check-in Reminder

Memory trick and short checklist

Mnemonic: ACTION = split (check in). THING = hyphen (check-in). If unsure, swap in register or desk to see what fits.

Action? Use two words: "I will check in."
Label or modifier before a noun? Use a hyphen: "check-in policy."
See "checkin"? Fix it-one word is usually wrong.

Similar mistakes to watch for

Apply the same test to other phrasal verbs that become nouns or adjectives.

log in (verb) → log-in (noun/adjective)
sign up (verb) → sign-up (noun/adjective)
follow up (verb) → follow-up (noun/adjective)

Wrong: I will login at 9.
Right: I will log in at 9.
Wrong: Complete the signup form.
Right: Complete the sign-up form.
Wrong: We need to followup on that issue.
Right: We need to follow up on that issue.

FAQ

Should I ever write "checkin" on official signs or forms?

No. Use check-in for signs or forms that name the desk or process. Checkin reads like a typo.

Is "check in" one word in British English?

No. Both American and British usage separate the verb and hyphenate the noun/adjective. Checkin is nonstandard in both.

Which is correct in an email subject: "Checkin Reminder" or "Check-in Reminder"?

Check-in Reminder is correct because the phrase labels the type of reminder.

Can I use "checkin" in quick chat messages?

People will usually understand it, but check in (verb) reads better. For clarity in written messages use two words for actions.

How can I fix multiple occurrences quickly in a long document?

Search for checkin and review each case. Replace with check in for actions or check-in for names or labels. A grammar tool can flag ambiguous uses.

Need help fixing a sentence?

Paste a sentence into the widget above for a quick correction, or run a targeted search-replace and apply the verb vs. noun test. A small manual check removes a visible error from emails, signs, and documents.