CC stands for “carbon copy” and is one of the three recipient fields available in every email platform: To, CC, and BCC. When you include someone in the CC field, they receive a copy of the email. Their address is visible to all other recipients, and they receive subsequent Reply All messages in the thread. The CC field is typically used to keep someone informed without expecting them to respond. Understanding when to CC — and when not to — is a core part of professional email etiquette. This guide covers the mechanics of CC, how it differs from To and BCC, appropriate and inappropriate uses, what to do when you are CC’d, and general rules for CC etiquette.

What Does CC Mean in Email and How Does It Work?

CC stands for “carbon copy,” and functionally represents a copy of an email sent to an additional addressee. If you include someone’s email address in the CC line, that person receives a copy of the email you send to the people in the To field. In Gmail, you will find the CC field as an option on the right-hand side of the To field. Click it to open a new line for CC recipients.

Gmail allows up to 100 CC recipients on a single email. There is also an option for BCC, or “blind carbon copy.” BCC works like CC, but the recipients are not visible to anyone else on the email, including other BCC recipients. For a full explanation of BCC, see our guide to BCC in email.

When you CC someone, their name and email address are visible to all other people on the email — everyone in the To field, CC field, and BCC field can see them. Whenever anyone chooses Reply All, all people in the To field and CC field receive a copy of the new message. CC’d people can Reply (which goes only to the person who drafted that specific message) or Reply All (which goes to all visible recipients). CC’d people often end up in the middle of extended email threads, whether that was the original intention or not. People can also be selectively removed from the conversation if it gets out of hand; removing someone does not delete previous messages from their inbox.

Why Use CC Instead of the To Field?

CC’d people receive the email just like people in the To field and have the same visibility and Reply/Reply All options. You can also add multiple people to the To field directly. So why use CC at all?

Some people understandably interpret CC as standing for “courtesy copy.” While the literal origin is “carbon copy,” the “courtesy copy” interpretation accurately describes how the CC field functions in practice. The To field serves as your primary recipient field — these are the people the message is directed to, and you generally expect a response from them. The CC field serves as your secondary field — these are the people who should see the message but are not expected to act on it. This distinction establishes a hierarchy that helps all recipients understand their role in the conversation and reduces unnecessary replies.

When Should You CC Someone in an Email?

Keeping someone in the loop. CCing is useful when you want someone to see an exchange without being part of it. For example, if your boss asks you for an update on a client, you could email the client directly and CC your boss. This keeps your boss informed of both your outreach and the client’s reply (assuming they Reply All), without requiring your boss to take any action.

Introducing new people. The CC field is effective for introductions. You can use the To field for your main recipient and the CC field to introduce additional people. All introduced parties see each other’s contact information and the context of the introduction.

Representing a team. If you are representing a team — introducing employees to a client for the first time, or making a group announcement — CCing your team members lets the recipient know who else is involved while making it clear that you are the primary point of contact.

Showing that you do not need a response. Including someone in the CC line tacitly signals that no response is required from them. This sets expectations without requiring you to explicitly say “no need to reply.” It is a useful way to keep people informed without adding to their action items.

When Should You Not CC Someone in an Email?

Copying up. “Copying up” means intentionally CCing someone’s boss or supervisor to make the recipient look bad, apply pressure, or be passive aggressive. Even in uncomfortable situations, this is widely regarded as unprofessional. If you have a legitimate grievance that a person is not willing or able to resolve, contact their supervisor directly rather than using a passive-aggressive CC. For more on this and other email etiquette rules, see our complete guide.

Sharing email addresses without consent. If you are introducing people, make sure you have their consent before sharing their email address with someone they do not know. Not everyone is comfortable having their contact information disclosed to strangers.

Expecting a response. If you need someone to answer a question or respond to your message, include them in the To field. The CC field signals that no action is required. The exception: if an email thread develops in a new direction, call out the CC’d person by name in the message or start a new thread with them as a direct recipient.

Anticipating an extended discussion. If you are about to start a long back-and-forth, every CC’d person will receive an alert for every new message in the thread. If they are not an active participant, the notifications will only annoy them. Keep the recipient list to a minimum for discussions that will generate many replies.

Inflating the group size. Adding as many possibly relevant people as you can think of to the CC line wastes everyone’s time. It is easy to add recipients, but every addition creates work for someone who may not need to see the message. In almost all cases, fewer recipients is the more efficient choice.

What Should You Do If You Are CC’d on an Email?

You probably do not need to respond. In most cases, CC’d people are not expected to reply to the message or to the thread, unless they are called out by name in the email body.

Your information is shared. Everyone on the thread can see your name and email address. If you were CC’d, your visibility is intentional (unlike BCC, where your presence is hidden).

Reply All goes to everyone. If you hit Reply All, your response will go to every email address that is publicly visible on the thread — all To and CC recipients. A direct Reply goes only to the person who drafted that specific message.

Not everyone follows standard CC practices. This is the most important point: not everyone understands or follows standard CC conventions. You may have been CC’d by accident. The sender may actually expect a reply from you. The sender may not understand the distinction between To and CC at all. Take the sender’s habits and the context of the message into account before deciding how to respond, especially if you do not know their email practices well.

What Are the General Rules for CC Etiquette?

Use CC sparingly. It takes only a click to add someone to the CC line, but that ease of use does not mean the feature should be used indiscriminately. Limit CC to situations where informing someone is genuinely valuable.

Use CC only for good. The CC field can be used to embarrass, reprimand, apply pressure, or be passive aggressive. All of these uses are unprofessional. Before adding someone to the CC line, ask yourself whether your intent is constructive and transparent.

Understand when To and BCC are better options. If you expect a response, the To field is the correct choice. If you want to copy someone without revealing their presence, BCC is the correct choice. Do not default to CC when another field serves the purpose better.