What blind carbon copy does and when to use it

Blind carbon copy, or BCC, lets you send an email to someone without the other recipients knowing they received it. When you put an address in the BCC field, that person gets the full email, but their address does not appear in the message — not in the To line, not in the CC line, nowhere. Everyone else on the email sees only the To and CC fields.

Use BCC when you need to loop someone in without alerting the main recipients. Common reasons: sending a copy to your own records, including a manager who should see the conversation but should not be visible to the client, or notifying a group of people without exposing all their email addresses to each other.

BCC is different from CC (carbon copy). When you CC someone, their address shows up for everyone to see. BCC keeps it hidden.

Key Takeaways

  • The BCC field is hidden by default in Outlook — you must turn it on in the message window before you can use it.
  • In Outlook on the web, click Options in the ribbon, then check the BCC box to reveal the field.
  • In Outlook desktop, click the BCC button in the ribbon, or go to File > Options > Mail > Compose messages and check "Show BCC field".
  • Anyone in the BCC field receives the email and can reply to all, but their address stays hidden from other recipients.
  • BCC does not hide the sender's address — everyone still sees who sent the message.

How to enable BCC in Outlook on the web

Outlook on the web (the version you access through a browser at outlook.com or through your organization's portal) hides the BCC field by default. To show it, open a new email message and look at the ribbon at the top.

Click the Options button in the ribbon. A small menu appears. Check the box next to BCC. The BCC field now appears below the CC field in your message. Type or paste the email addresses you want to BCC, then compose and send as normal.

This setting applies only to the current message. The next time you open a new email, you will need to enable BCC again unless you change the default setting in your account preferences.

How to enable BCC in Outlook desktop

Outlook desktop (the application you download and install on your computer) also hides BCC by default, but you have two ways to turn it on.

Quick method for one message: Open a new email. In the ribbon at the top, look for the BCC button and click it. The BCC field appears immediately below the CC field. Type the addresses and send.

Permanent method: If you use BCC often, you can make it always visible. Click File in the top left, then Options. In the left sidebar, click Mail. Scroll down to the "Compose messages" section and check the box labeled Show BCC field. Click OK. Now BCC appears in every new message you write.

What happens when you send a BCC email

When you hit Send, the email goes to everyone in the To field, everyone in the CC field, and everyone in the BCC field. All three groups receive the identical message with the same subject and body.

The To and CC recipients see the To and CC fields in their inbox. They do not see the BCC field or the addresses in it. The BCC recipients see the To and CC fields, but not themselves — they see the message as if they were not there at all.

If a BCC recipient clicks Reply All, their reply goes to everyone in the To and CC fields, but not to the other BCC recipients. This is because the other BCC recipients are not visible in the message header.

Common mistakes to avoid

The most common mistake is forgetting that BCC recipients can still see the To and CC fields. If you BCC your manager on an email to a client, the client cannot see your manager was copied, but your manager can see the client's address and the full conversation. Make sure the BCC recipient is someone who should see the entire exchange.

Another mistake is assuming BCC hides the sender. It does not. Everyone — To, CC, and BCC — sees who sent the message. BCC only hides the BCC recipients themselves.

Do not use BCC to secretly monitor someone or to copy someone on a message without their knowledge if they might later discover it. BCC is useful for legitimate record-keeping and workflow reasons, but using it to deceive people can damage trust and may violate your organization's email policy.

BCC versus CC: when to use each

Use CC when you want the recipient to see that they are included and when you want other recipients to know they are there. Example: copying a colleague on a client email so the client knows both of you are involved.

Use BCC when you want someone to have the information but do not want the main recipients to know they are copied. Example: sending a copy to your own email account for your records, or looping in a supervisor without the external party knowing.

If you are unsure whether to use BCC, ask yourself: would the main recipient be okay knowing this person received the email? If yes, use CC. If no, use BCC — but make sure you have a legitimate reason to keep it hidden.

Frequently Asked Questions

Can BCC recipients see each other?

No. Each BCC recipient sees only the To and CC fields. They cannot see other BCC recipients or even that they themselves were BCC'd. From their perspective, they received a regular email.

If someone replies to a BCC email, do all the BCC recipients see the reply?

Only if the person who replied used Reply All and the reply went to the To and CC recipients. BCC recipients do not automatically see replies unless they are also in the To or CC field of the reply.

Does BCC work the same way in Outlook mobile apps?

The Outlook mobile app for iPhone and Android does not currently show a BCC option in the compose window. If you need to use BCC, you will need to use Outlook on the web or Outlook desktop.

What if I accidentally put someone in BCC instead of CC?

If you have not sent the message yet, you can move them. Delete their address from the BCC field and type it into the CC field instead. If you have already sent it, you cannot unsend it in most cases, so you may need to send a follow-up explaining the situation.

Is BCC visible in the email header if someone forwards the message?

No. When someone forwards an email, the BCC field does not carry forward. The person forwarding sees only the To and CC fields, and that is all the new recipient sees.