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 (short for carbon copy), that person gets a full copy of your email. Unlike the To field, which holds the main recipients, CC is for people who need to see the message but are not the primary audience. Everyone who receives the email — whether in To, CC, or BCC — can see all the addresses in both the To and CC fields.

The term comes from old office practice. Before email, people used carbon paper to make duplicate copies of letters as they typed. A secretary might put carbon paper between sheets so that pressing down with a typewriter would create copies for other people to see. Email's CC field works the same way: it creates a visible copy for people who should be informed but are not the main recipient.

Key Takeaways

  • CC sends a copy of your email to additional people, and everyone can see that those people received it.
  • Use CC when someone needs to see the message for information or context, but the email is not primarily directed at them.
  • BCC (blind carbon copy) sends a copy to someone without showing their address to other recipients.
  • All email services — Gmail, Outlook, Apple Mail, and others — have CC fields in the compose window.

The difference between To, CC, and BCC

The To field holds the main recipients — the people you are writing to directly. They are the ones expected to read and act on your message. The CC field holds people who should see the message and know it was sent to them, but they are not the primary audience. The BCC field (blind carbon copy) sends a copy to someone without revealing their address to anyone else on the email.

A practical example: you send an email to your manager (To field) about a project delay. You CC your team lead so she knows about the issue. You BCC your HR contact if you are documenting a problem — the HR contact sees the email, but your manager and team lead do not see that HR was copied. Each field serves a different purpose depending on who needs to know and whether they should know who else is seeing it.

When to use CC instead of To

Use CC when the email is not primarily directed at someone, but they should be in the loop. If you are writing to a vendor about a contract and your legal team needs to review it, CC your legal contact. If you are confirming a meeting time with a client and your boss should know it happened, CC your boss. The CC recipient gets the full message and can reply to all if needed, but they are not the main person you are addressing.

CC is also useful for transparency. If you are sending feedback to a colleague, CCing their manager makes the feedback visible to leadership without hiding it. This is different from BCC, which would hide the manager's involvement. Use CC when visibility is the point; use BCC when you need someone to have information without others knowing they do.

When to use BCC

BCC is for situations where someone needs a copy but should not be visible to other recipients. If you are sending an email to a group of people who do not know each other and should not see each other's addresses, use BCC. A common example: a newsletter or announcement sent to many people. You put all the addresses in the BCC field so each person receives it but cannot see the full list of recipients.

BCC is also used for documentation. If you need a record of an email for legal or HR purposes, you can BCC yourself or a compliance contact. The other recipients will not know a copy was sent elsewhere. However, use BCC carefully in work settings — if people discover they were BCC'd without knowing it, it can damage trust. Most workplaces have policies about when BCC is appropriate.

How to use CC in different email services

In Gmail, open a new email and click "Compose". The To field appears by default. Click the small arrow or "CC" link next to the To field to reveal the CC and BCC fields. Type the address you want to CC and press Enter or Tab to add it. You can add multiple addresses separated by commas.

In Outlook (web or desktop), click "New Message" and the To field opens. Click "Cc" or "Bcc" in the ribbon or message header to show those fields. Type the address and add as many as you need. In Apple Mail, open a new message and use the menu View > Message Headers to show CC and BCC fields, or press Command+Shift+C to toggle CC on and off.

Most email services work the same way: compose a message, reveal the CC field, and type the address. If you are replying to an email that already has people CC'd, they stay CC'd unless you remove them. If you click "Reply All", everyone in To and CC gets your response.

Common mistakes with CC

One frequent mistake is using CC when you should use To. If someone is a main recipient and should know they are the primary audience, put them in To, not CC. Putting someone in CC when they expect to be in To can make them feel like an afterthought.

Another mistake is CCing too many people. If you CC everyone on your team for every email, the CC field loses its meaning and people stop paying attention. Reserve CC for people who actually need to see the message. A third mistake is forgetting that everyone in CC can see everyone else's address. If you are CCing people from different organizations or departments who should not see each other's contact information, use BCC instead.

Finally, be careful with "Reply All". If you reply to an email where you were CC'd, your reply goes to everyone in To and CC. Sometimes you only meant to reply to the sender. Check the button you click — "Reply" goes only to the sender, while "Reply All" goes to everyone.

Why the term "carbon copy" still exists

Email adopted the term "carbon copy" from office typewriter days because the function is identical: creating a visible copy for someone else to see. The abbreviation CC stuck because it was already familiar to anyone who had worked in an office. Even though no one uses carbon paper anymore, the term remains in every email service worldwide.

The same is true for BCC — "blind" carbon copy — which refers to making a copy that others cannot see. These terms are now over 50 years old in computing, but they describe the function so clearly that email designers never replaced them with new names. You will see CC and BCC in every email service you use.

Frequently Asked Questions

Can someone tell if they were CC'd instead of put in the To field?

Yes. If they look at the email header, they can see which field their address was in. However, most people do not check this. The practical difference is that being in To suggests you are the main recipient, while CC suggests you are being informed. If it matters to the recipient, they will notice from context.

If I CC someone, can they see my reply to the original sender?

Only if you click "Reply All". If you click "Reply", your message goes only to the sender. If you click "Reply All", everyone in To and CC gets your response. Check which button you are using before you send.

What happens if I CC someone on a reply?

They receive your reply and can see the full conversation thread. They will see all previous messages in that email chain. If they were not CC'd on the original email, they will see it in your reply and can read the context.

Is it rude to CC someone without asking?

It depends on context. In most work settings, CCing a manager or colleague on an email is normal and expected. CCing someone to make a point or create a record can feel aggressive if done without warning. If you are unsure, it is fine to mention it in the email: "I am CCing my manager so she is aware of this issue."

Can I remove someone from CC on an email I already sent?

No. Once an email is sent, you cannot change who received it. If you need to correct a mistake, you can send a follow-up email explaining the error. Some email services let you "unsend" a message within a few seconds of sending it, which would prevent the CC recipient from ever seeing it.