How to say "check-in" in Japanese

• チェックインCommon
  noun, suru verb, intransitive verbCovers check-in in the general sense: registering on arrival at a hotel, airport or event. The common katakana loanword — say this when checking in at the front desk.
  何時いつからチェックインできますか。↗

  What time do you start check-in?
• 搭乗手続きとうじょうてつづき
  nounLiterally 'boarding procedures': the check-in you do at the airport before a flight. Less common than the loanword and not used for hotels — it is really about the procedures for boarding a plane.

「チェックイン」 is the common, all-purpose word for check-in, at a hotel or before a flight; 「搭乗手続き」, literally 'boarding procedures', is the less common word for the airport check-in specifically.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• チェックインcheck-in
• 搭乗手続きとうじょうてつづきboarding procedures