につき

につき goes after a noun and has two meanings: "due to" and "per". Both belong to signs, notices, price lists and formal documents.

After a noun for a reason, につき means "due to", "because of". A notice often stops right after the result.

After a number with a unit, につき means "per", "for each".

Register

In speech, the reason use sounds like reading out a sign. Say ので or から instead, or ため in polite speech. For "per", conversation uses で or nothing at all.

"Concerning"

In formal writing, につき can also mean "about", like について.