The CC and BCC fields when sending email work similarly. CC stands for “carbon copy,” while BCC stands for “blind carbon copy.” Though these terms may have been immediately obvious when email was invented, they’re antiquated today.

CC and BCC are both ways of sending copies of an email to additional people. However, you can also send copies of an email to additional people by specifying multiple addresses in the To field.

Carbon Copying Explained

The abbreviation CC comes from “carbon copy.” By placing a sheet of carbon paper between two pieces of paper, the pressure from writing on the first piece of paper will push the ink from the carbon paper down onto the second piece of paper, producing an additional copy of the document. Like a physical carbon copy, a CC is a way of sending additional copies of an email to other people. Some people refer to CC as “courtesy copy,” which better describes what a CC actually is. CC is often used as a verb, as in “I CC’d him on the email.”

Image Credit: Holger Ellgaard on Wikimedia Commons

CC vs. BCC

When you CC people on an email, the CC list is visible to all other recipients. For example, if you CC bob@example.com and jake@example.com on an email, Bob and Jake will both know that the other received the email, as well.

BCC stands for “blind carbon copy.” Unlike with CC, no one but the sender can see the list of BCC recipients. For example, if you have bob@example.com and jake@example.com in the BCC list, neither Bob nor Jake will know that the other received the email.

Someone on the BCC list can see everything else, including the CC list and the contents of the email. However, the BCC list is secret—no one can see this list except the sender. If a person is on the BCC list, they’ll see only their own email on the BCC list.

To vs. CC

The To and CC fields work similarly. Whether you put four email addresses in the To field or put one email address in the To field and three in the CC field, the four people will all receive the same email. They’ll also be able to see the email address of every other recipients in the To and CC fields.

When it comes to email etiquette, the To field is generally for the main recipients of your email. The CC field is for sending a copy to other interested parties for their information. This isn’t a concrete rule, and usage of To and CC varies.

For example, let’s say your boss wants you to email a customer in response to a complaint. You’d put the customer’s email address in the To field and your boss’s email address in the CC field, so your boss would receive a copy of the email. If you didn’t want the customer to see your boss’s email address, you’d put your boss’s address in the BCC field instead.

When to Use CC and BCC

CC is useful when:

You want someone else to receive a copy of an email, but they aren’t one of the primary recipients. You want the recipients of the message to know the other people who have been sent the message.

BCC is useful when:

You want someone else to receive an email, but you don’t want the primary recipients of the email to see you’ve sent this other person a copy. For example, if you’re having a problem with a fellow employee, you might send them an email about it and BCC the human resources department. HR would receive a copy for their records, but your fellow employee wouldn’t be aware of this. You want to send a copy of an email to a large number of people. For example, if you have a mailing list with a large number of people, you could include them in the BCC field. No one would be able to see anyone else’s email address. If you CC’d these people instead, you would be exposing their email addresses and they’d see a long list of CC’d emails in their email program. You could even put your own email address in the To field and include every other address in the BCC field, hiding everyone’s email address from each other.

BCC, Replies, and Email Threads

Note that BCC doesn’t function like CC when it comes to email threads. For example, if you send an email to bob@example.com and BCC jake@example.com , Jake will receive the original email you send. However, if Bob replies, Jake won’t get a copy of Bob’s reply. Bob’s email program can’t see that Jake ever received the email, so it doesn’t send him a copy of the reply.

Of course, you can continue to BCC Jake on future emails or forward him a copy of the reply. It’s also possible that Bob could erase Jake’s email from the CC field and reply directly to you if you CC’d Jake instead. However, people are much more likely to receive all replies in an email thread if you CC them. You’ll have to keep them in the loop if you’re BCC’ing them.

In practice, a lot of this can come down to email etiquette and different people will use these fields differently—particularly the To and CC fields. Don’t be surprised if you see them used differently.