What Does CC Mean in Email? CCing Explained

Short answer: CC stands for carbon copy. CCing someone (also written cc'ing) means adding them to the Cc line of an email so they get a copy of a message that is addressed to someone else. Everyone on the email can see who was CC'd, and CC usually signals "for your information": the people in To are expected to act or reply, the people in Cc are being kept in the loop.

That's the whole idea. The rest of this guide covers where the term comes from, how to spell it, when CC helps and when it gets in the way, and how it differs from BCC.

What does CC mean in email?

CC is short for carbon copy. Before photocopiers, people made a duplicate of a letter by putting a sheet of carbon paper between two pages, so whatever was typed on the top sheet came through on the one underneath. A note such as "cc: J. Smith" at the bottom of the letter told the reader who else had been sent a copy.

Email kept the name. The standard that defines the email format, RFC 5322, describes the Cc field as holding the addresses of others who are to receive the message, "though the content of the message may not be directed at them." You'll sometimes hear it read as courtesy copy, which describes how it's used today rather well, but carbon copy is the original meaning.

In practice, an email has three address lines:

Field	Who goes there	Who can see them
To	The people the email is for, who should read it and usually act or reply	Everyone on the email
Cc	People who should know about it but aren't expected to act	Everyone on the email
Bcc	People who get a copy without the others knowing	Only the sender (and, in some apps, the Bcc recipient)

Technically, a CC recipient gets exactly the same message as a To recipient, including every attachment. The difference is the signal it sends.

What does CCing someone mean?

To CC someone, or to be CCing them, is to put their address in the Cc field. If you've been CC'd on an email, it means the sender wanted you to see it but didn't address it to you. A few things follow from that:

You aren't normally expected to reply. If the sender wants something from you, they should say so in the message or move you to the To line.
Everyone else on the email can see that you were copied, and you can see them.
If anyone clicks Reply All, you'll get their reply too, because Reply All goes to everyone in To and Cc.
When you're added to an existing thread, you only receive what's in that message. You see earlier replies only if they're quoted below it.

CCing or cc'ing: how to spell it

There's no single rule, and you'll see every version at work. Dictionaries that list cc as a verb tend to use an apostrophe: Oxford Learner's Dictionaries gives cc's, cc'd and cc'ing. Many people drop the apostrophe (ccing, cced) or write it in capitals (CCing, CC'd, CC'ed), and all of these are understood.

Form	Common spellings	Example
Present	cc, CC	Please cc me on the reply.
Third person	cc's, CCs	She always cc's her manager.
Past	cc'd, cc'ed, CC'd, cced	I cc'd the whole team.
-ing form	cc'ing, ccing, CCing, CC-ing	I'm cc'ing Sam so he has the details.

Pick one style and stick with it in a document. If your company has a style guide, follow that. In an email itself, the usual phrasing is "I've copied Sam" or "cc'ing Sam for visibility".

How to CC someone on an email

Every email app has a Cc field just below or beside the To field. Type the address there, separating several addresses with commas. Where to find it:

Gmail on a computer: click Compose, add your main recipients in To, then add the others in the Cc field. The keyboard shortcut is Ctrl+Shift+C on Windows or Command+Shift+C on a Mac (Gmail Help, Gmail shortcuts).
Outlook.com and Outlook on the web: select Cc on the right side of the To line (Microsoft).
Mail on iPhone: in a new message, tap the Cc/Bcc field, then tap Cc and enter the names (Apple).
Mail on Mac: in the new message window, type the addresses in the Cc field (Apple).

For BCC steps in Gmail, Outlook, Apple Mail and on iPhone, see our guide to what BCC means and how to use it.

When should you CC someone?

CC works best when someone needs to know about a conversation but isn't the one who has to act. Good reasons:

Keeping a manager or stakeholder informed of a decision or progress on a project.
Introducing a new colleague or contact to a group that should know who they are.
Handing a task to a colleague, with the client or the old owner copied so everyone knows who's on it now.
Keeping a written record when several people need to see the same agreement or instructions.
Bringing someone into an existing thread so they have the background.

When not to CC

To pressure a colleague by copying their boss on a disagreement. People notice, and it rarely helps.
Out of habit. Every extra name is another inbox to clutter, and it blurs who is supposed to respond.
When the recipients don't know each other and shouldn't see each other's addresses, such as customers, parents or event attendees. Use BCC or a mailing tool instead. The UK data protection regulator, the ICO, warns that putting people in CC instead of BCC discloses their email addresses, and treats an address that identifies a person as personal data (ICO).
When the content is sensitive. Anyone in CC can forward the message.

CC email etiquette

Say who you've added and why. A short line such as "Copying Priya, who handles invoicing" saves everyone guessing.
Put the person who must act in To. If you need an answer from someone, they belong in To, not Cc.
Think before Reply All. If your reply only matters to the sender, reply to the sender.
Move people to BCC when you take them off a thread. "Moving Sam to bcc to spare his inbox" is a polite way to let someone drop out of the replies.
Check the thread before you add people. Everyone you add can read whatever is quoted below your message, including earlier replies they weren't meant to see.
Check attachments. CC recipients get every attachment, so don't copy anyone who shouldn't see the files.

CC vs BCC: the difference

CC and BCC both send a copy of the message. The difference is who can see the copied addresses.

	CC (carbon copy)	BCC (blind carbon copy)
Visible to other recipients	Yes, everyone sees CC addresses	No, BCC addresses are hidden
Gets Reply All replies	Yes	No
Receives attachments	Yes	Yes
Typical use	Keeping colleagues or stakeholders informed	Group emails where recipients shouldn't see each other, or a quiet copy to yourself
Main risk	Exposing addresses, clutter from Reply All	A BCC recipient who hits Reply All reveals they were copied

A simple rule: use CC when you want everyone to know who else is reading, and BCC when you don't. One thing to know about BCC is that a hidden recipient who clicks Reply All shows up to everyone, so tell anyone you BCC not to reply to all.

Our guide to what BCC means in email explains how hidden recipients work behind the scenes, what happens when they reply, and how to add them in Gmail, Outlook and Apple Mail.

Managing the email you get CC'd on

Disclosure: we make Canary Mail. If CC threads bury the emails that need you, an inbox that sorts mail for you can help. Canary Mail is an email app for Mac, iPhone, iPad, Windows and Android that works with Gmail, Outlook, iCloud, Yahoo, Exchange and other IMAP accounts. Its free plan includes AI inbox sorting and unlimited accounts on 2 devices, and the sorting runs on your device. The Growth plan ($36 a year) adds AI summaries, handy for long CC threads you only need the gist of. More than 2 million people use it, and Apple has featured it on the App Store and the Mac App Store.

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Frequently asked questions

What does CC stand for in email?

Carbon copy. The name comes from the carbon paper once used to type a duplicate of a letter. In email it means sending a copy to people who should see the message but aren't its main recipients.

Is it CCing or cc'ing?

Both are used and both are understood. Dictionaries that list cc as a verb usually write cc'ing and cc'd, with an apostrophe; CCing and cced are common in everyday email. Choose one style and use it consistently.

Should I reply if I'm CC'd on an email?

Usually not. Being CC'd means the sender is keeping you informed. Reply if you're asked a question, if you have information the others need, or if something in the email is wrong. If you do, think about whether Reply All is needed.

Can CC recipients see each other?

Yes. Everyone in To and Cc can see every address in both fields. Only BCC recipients are hidden.

Do CC recipients get attachments?

Yes. Everyone in To, Cc and Bcc gets the same message, attachments included. To leave someone out of a file, send them a separate email.

How many people can you CC on an email?

It depends on your provider. Gmail counts To, Cc and Bcc together and limits a single email to 500 recipients in total. Other providers set their own limits, and big lists are better sent with BCC or a mailing tool.

What Does CC Mean in Email? CCing Explained, With CC vs BCC (2026)