Carbon copy is a way to send the same email to multiple people at once, with everyone able to see who else received it

When you put someone's address in the CC field of an email, that person gets a full copy of the message. Unlike the BCC field (blind carbon copy), everyone who receives the email — whether in the To, CC, or BCC lines — can see the CC recipients' addresses. The term comes from the days of typewriters, when people used carbon paper to make duplicate copies of letters as they typed.

CC is useful when you want someone to be informed about a conversation but they are not the primary recipient. For example, you might CC your manager on an email to a client, or CC a colleague who needs to know about a project update. The key difference from the To field is that CC recipients are not expected to take action or respond — they are there to stay informed.

Key Takeaways

  • CC stands for carbon copy, and everyone on the email can see who is in the CC field.
  • Use CC when you want someone informed but not as a primary recipient of the message.
  • BCC (blind carbon copy) hides recipients from each other and should be used when privacy matters.
  • CC recipients can reply to all and include everyone, so think carefully about who needs to see the conversation.

The difference between To, CC, and BCC

The To field is for primary recipients — the people you are directly addressing and who are expected to read and possibly respond to your message. When you put someone in the To field, they know the email is meant for them.

CC recipients get the same message but are marked as secondary. They can see that they were CC'd, and they can see everyone else on the email. If a CC recipient clicks Reply All, their response goes to everyone — the original sender, all To recipients, and all other CC recipients. This is why CC is best used when you want someone in the loop but do not expect them to be part of the back-and-forth.

BCC (blind carbon copy) is different: BCC recipients receive the email, but no one else can see that they received it. If you BCC someone, the To and CC recipients have no way of knowing that person got the message. BCC recipients also cannot see other BCC recipients. This is useful for privacy — for example, when you are sending the same message to a large group and do not want to expose everyone's email addresses to each other.

When to use CC in work and personal emails

CC works well when you want to keep someone informed without making them a primary decision-maker. In a work setting, you might CC your manager on an email to a vendor so she knows what you promised. You might CC a colleague on a client update so they understand the project status without needing to respond.

The risk with CC is that it can create long email chains where many people are copied but few are actually reading or contributing. Before you CC someone, ask yourself whether they truly need to see this conversation. If the answer is "just to keep them in the loop," CC is appropriate. If the answer is "because I am not sure if they care," consider whether an email summary or a separate message would be better.

In personal emails, CC is less common but still useful. You might CC a family member on an email about a shared event, or CC a friend on a message to a group so everyone knows who is involved. The same rule applies: everyone can see the CC line, so only include people who are comfortable having their address visible to the other recipients.

Why everyone can see the CC field

Email systems show the CC field to all recipients because the original purpose of carbon copy was transparency. When you physically made a carbon copy of a letter, everyone who received a copy knew that others had received one too. Email preserved that principle: CC is meant to be visible, so no one is surprised to learn later that someone else was reading along.

This visibility is actually a feature, not a bug. It prevents people from secretly copying others into conversations. If you want to include someone without others knowing, that is what BCC is for. But if you use CC, you are being transparent about who is in the conversation.

Common mistakes people make with CC

One frequent mistake is CCing too many people. This creates noise in inboxes and makes it harder for anyone to know whether they should respond. If you are CCing more than three or four people, consider whether a group email or a message to a specific list would be clearer.

Another mistake is forgetting that CC recipients can Reply All. If you CC someone on a sensitive conversation, remember that if they reply, their message goes to everyone. This can lead to awkward situations where someone says something meant for one person but ends up in front of the whole group.

A third mistake is using CC when BCC would be more appropriate. If you are sending the same message to many people who do not know each other — for example, a job posting to multiple candidates — BCC protects everyone's privacy. Using CC in that situation exposes all their email addresses to each other, which most people do not want.

How to CC someone in Gmail, Outlook, and other email services

In Gmail, open a new email and click the CC link next to the To field. Type the email address of the person you want to copy, and they will be added to the CC line. You can add multiple CC recipients by typing each address and pressing Enter or Tab between them.

In Outlook, the CC field is visible by default next to the To field. Click in the CC box and type the address. If you do not see the CC field, look for a link that says "Cc" or "Show Cc" — some versions hide it until you click.

In Apple Mail, the CC field appears in the compose window. If it is not visible, go to the View menu and make sure "CC Address Field" is checked. Most other email services work the same way: look for a CC button or link in the compose area, or the field may already be visible next to To.

Frequently Asked Questions

Can I CC someone without them knowing?

No — if you put someone in the CC field, everyone on the email can see their address. If you want to include someone without others knowing, use BCC instead. BCC recipients are hidden from all other recipients.

What happens if a CC recipient replies to all?

Their reply goes to everyone: the original sender, all To recipients, all CC recipients, and all BCC recipients (though BCC recipients cannot see each other). This is why you should only CC people who you are comfortable having participate in the conversation.

Is it rude to CC someone?

Not if it is appropriate. CCing someone to keep them informed is normal and expected in most workplaces. It becomes rude only if you CC someone to make a point, embarrass them, or drag them into a conflict they are not part of.

Should I CC my boss on everything?

No. CC your boss when they need to know about a decision, a problem, or a commitment you have made. Do not CC them on routine updates or every email you send. This creates unnecessary email volume and can make it seem like you do not trust your own judgment.

What is the difference between CC and Reply All?

CC is used when you are composing a new email and want to include someone as a secondary recipient. Reply All is used when you are responding to an email that was already sent to multiple people, and you want your response to go to everyone who received the original message.