What does RE mean in an email? In an email subject line, “RE:” means “regarding” or “in reference to.” Email programs add it automatically when you reply to a message, so “RE: Budget meeting” tells the reader this is a reply in the “Budget meeting” conversation. The term comes from the Latin in re, meaning “in the matter of.”
What does RE mean in email at work?
When you hit Reply, your email app copies the original subject and adds “RE:” in front. That small prefix does two jobs:
- It tells the reader the message is a reply, not a new topic.
- It helps email apps group messages into a thread, so the whole conversation stays together.
RE is not an abbreviation for “reply,” even though most people now read it that way. Long before email, business letters and memos used “Re:” to introduce the subject line. Many people still use it in formal letters, such as “Re: Account #4521.”
You may see it written as RE:, Re: or re:. They all mean the same thing. Some email apps in other languages use different prefixes, such as “AW:” in German.
Examples of RE in emails and messages
Reply subject: “RE: Q3 marketing plan”
Long thread: “RE: RE: RE: Office move dates” (a sign it may be time to start a new thread)
Formal letter: “Re: Request for extension on invoice #1187”
Updated subject: “RE: Office move dates (now confirmed for June 3)”
RE vs FW vs CC
| Prefix or field | Means | When you see it |
|---|---|---|
| RE: | Regarding; a reply | Added when you click Reply or Reply All |
| FW: or FWD: | Forwarded | Added when you forward a message to someone new |
| CC | Carbon copy | A field for people who should be kept informed |
Learn more about CC and BCC.
How to use RE correctly
- Let your email app add it. Don’t type “RE:” on a brand-new email. It can look like spam or confuse threading.
- Start a new thread for a new topic. Replying to an old email about something unrelated buries your message.
- Update the subject when the topic changes. Keep the RE: and add a short note, like “(decision needed).”
- Clean up long chains. If you see “RE: RE: RE: FW: RE:”, consider a fresh subject line.
- Use “Re:” in formal letters to state the subject clearly, such as a case or account number.
Related terms
Browse more short forms in our Workplace Acronyms hub.
FAQ
Does RE stand for reply?
Not originally. RE comes from the Latin “in re,” meaning “in the matter of,” and is read as “regarding.” Because email apps add it to replies, many people now think of it as “reply.”
Why does my email say RE: RE: RE:?
Some email apps add a new RE: each time someone replies, and others don’t remove duplicates. It means the thread has had several replies.
What is the difference between RE and FW?
RE marks a reply to the people already in the conversation. FW or FWD marks a message that has been forwarded to someone new.
Should I type RE in a new email?
No. Adding RE to a new email can make it look like a reply or spam. Let your email app add it when you reply.
