The basic steps depend on which app you're using
Adding someone to a group chat works differently on each platform. On iMessage (Apple's texting app), you tap the group name at the top of the conversation, then tap "Add Contact" and select the person. On WhatsApp, you open the group, tap the group name, scroll to "Participants", and tap the plus icon. On Facebook Messenger, open the group conversation, tap the group name at the top, then tap "Add People" and search for the person's name. On Slack (used mostly for work), click the group name, then click "Add members" and type the person's username or email.
The person you add will see the entire conversation history in most apps — they can read everything that was said before they joined. Some apps let you change this setting, but the default is to show the full chat. Once someone is added, they can see all future messages and participate when ready.
If you do not have permission to add people (for example, in some work groups where only an admin can add members), you will see a message saying you cannot add contacts, or the "Add" button will be grayed out. In that case, ask the group admin or the person who created the chat to add them instead.
Key Takeaways
- The steps to add someone differ by app — iMessage uses "Add Contact", WhatsApp uses the plus icon next to "Participants", and Messenger uses "Add People".
- New members can usually see all previous messages in the chat unless the group admin has turned off that setting.
- Some groups restrict who can add people, and only an admin or the group creator can add new members in those cases.
- The person you add will be notified that they have been added to the group and will see the group name and all members listed.
Adding someone on iMessage (iPhone, iPad, Mac)
Open the group conversation you want to add someone to. Look at the top of the screen where the group name appears — tap or click on it. A menu will open showing all the people in the group and options to manage the conversation.
Look for "Add Contact" or a plus icon. Tap it, then search for the person's name in your contacts or type their phone number. Select their name from the list and confirm. They will be added when ready and will see a notification that they joined the group.
Adding someone on WhatsApp
Open the group chat. At the top of the screen, tap the group name. This opens the group info page. Scroll down until you see "Participants" with a list of everyone in the group. Tap the plus icon next to "Participants" or look for "Add Participant".
Search for the contact you want to add by typing their name. You can only add people who are already in your phone's contacts and who use WhatsApp. Once you select them, they will be added to the group and notified when ready.
Adding someone on Facebook Messenger
Open the group conversation. Tap or click the group name at the very top of the chat window. This opens the group details panel on the right side of the screen (on desktop) or as a new screen (on mobile).
Look for "Add People" or a plus icon near the members list. Tap it and search for the person by name or username. Select them from the results and they will be added. They will see a notification that they were added to the group and can start reading and sending messages right away.
Adding someone on Slack (for work groups)
Click on the channel or group name at the top of the conversation. A details panel will open on the right side showing members and settings. Look for "Add members" or a plus icon next to the members list.
Type the person's name, email, or username. Slack will show matching results — select the correct person. If the person is not in your Slack workspace yet, you may need to invite them to the workspace first before adding them to the specific group. Some workspaces restrict who can add members, so you may need to ask a workspace admin if you do not see the "Add members" option.
What happens when someone is added to a group
The new member will receive a notification that they have been added. On most apps, they will see the full conversation history — all messages sent before they joined. This means they can read the entire chat to catch up on what they missed.
Some group admins turn off this setting so new members only see messages sent after they join. If your group has this rule, the new person will only see future messages. Either way, they can participate and send messages as soon as they are added.
When you cannot add someone to a group
Some groups have restrictions that prevent regular members from adding new people. This is common in work groups, professional channels, and some private groups. If you try to add someone and see an error message or a grayed-out button, the group is restricted.
In this case, contact the group admin or the person who created the group and ask them to add the person for you. Tell them the name or contact information of the person you want to add. The admin will have the permission to add them even if you do not.
Frequently Asked Questions
Can someone see messages from before they were added to the group?
Usually yes — most apps show new members the entire chat history so they can catch up. However, some group admins turn off this setting, and then new members only see messages sent after they join. Check your group settings or ask the admin if you are unsure.
What if the person I want to add is not in my contacts?
You will need their phone number, email, or username depending on the app. For iMessage and WhatsApp, they need to be in your phone's contacts first. For Messenger and Slack, you can search by name or email even if they are not saved as a contact.
Can I add someone to a group without them knowing?
No — all apps notify the person when they are added to a group. They will see a notification and the group will appear in their chat list. There is no way to add someone silently.
What if I accidentally added the wrong person?
You can remove them if you have permission. Open the group info, find their name in the members list, and look for a remove or delete option (usually a minus sign or trash icon). If you cannot remove them, ask a group admin to do it.
Do I need the person's phone number to add them?
It depends on the app. iMessage and WhatsApp require a phone number or a contact saved in your phone. Facebook Messenger and Slack let you search by name or username instead. Check which app your group uses to know what information you need.