Mass text vs group chat vs group MMS: which should a business use

You have 300 customers to reach about a schedule change. On a phone, the quickest option looks like adding everyone to one thread and hitting send. It feels efficient until the first customer replies "who is this?" and 299 other people get that reply. A few minutes later, someone screenshots a thread that shows every customer's phone number.

This guide compares three ways a business can send one message to many people: a mass text (one-to-one broadcast), a group chat, and a group MMS. It covers privacy, reply-all, opt-outs, carrier limits and cost. For nearly every business send, the answer is one-to-one broadcast. There are also a few narrow cases where a group thread is fine.

The three options, defined

The terms get mixed up, so here is how we use them:

• Mass text (one-to-one broadcast): the same message goes to each person as a separate text. Each recipient sees a private thread with your number. Replies come back only to you. Most business texting platforms call this a campaign or a bulk send.
• Group chat: a shared thread, usually iMessage between iPhones, where every participant sees every message and every reply.
• Group MMS: the carrier version of a group chat. When a thread includes non-iPhone users, phones fall back to MMS. Everyone gets the same picture-message thread, and replies go to everyone.

The difference that matters for a business: in a group thread, recipients can see each other. In a mass text, they can't.

Privacy: who sees whose number

In a group chat or group MMS, every participant can see every other participant's phone number. For a business, that creates three problems.

1. You've disclosed customer data. Customers gave their number to you, not to the other 299 people on your list. Exposing it is a trust problem at minimum. In healthcare, finance or anything involving minors, it can be a real compliance problem.
2. Competitors and spammers can collect your list. One screenshot hands over your whole customer base.
3. Customers start contacting each other. Once people can see each other's numbers, some of them will message each other, and your business is the reason they could.

A one-to-one send has none of these issues. Every recipient sees a thread that contains only them and you.

Reply-all and the opt-out problem

Reply-all chaos

In a group thread, every reply reaches everyone. "Thanks!", "Stop texting me" and "Is this a scam?" all go to the whole group, and each one sets off more notifications for people who didn't ask for them. A group of a few dozen people can produce hundreds of unwanted notifications from a single announcement. Those people end up annoyed with your business, not with the person who replied.

STOP doesn't work cleanly in a group

Opt-out handling is where group threads fall apart for business use. When someone texts STOP in a one-to-one thread, the request is clear: this number wants no more messages from this sender. On Ready, inbound STOP or UNSUBSCRIBE is honored automatically, and the opt-out applies across campaigns, so that contact can't be messaged again.

In a group MMS, a STOP is ambiguous. It's unclear who it's addressed to, and nothing on the carrier side removes that one person from the thread. They either leave the conversation, which not every phone supports for MMS groups, or they keep receiving messages. Honoring opt-outs is part of TCPA practice. A channel that can't reliably honor them is a channel you shouldn't use for marketing or for bulk notifications. Our post on mass texting legality and rules covers what the law expects.

Carrier and device limits

Group threads have hard ceilings that one-to-one sends don't:

• Group size caps. Phones and carriers limit how many people can be in a group MMS. The cap varies by device and carrier, and it is far below a typical customer list. Past that limit, messages fail or the group splits unpredictably.
• Business routes generally don't support group MMS. Registered A2P 10DLC traffic, the route carriers want business texts on, is built for one-to-one sends. Most business texting providers can't start a group MMS from a registered number.
• Unregistered traffic gets filtered. If you try to work around this by sending from a personal phone, you're sending business traffic outside registration, and carriers filter it. Our 10DLC explainer explains why registration matters. Our comparison of texting apps vs business platforms covers what breaks when you text from consumer apps.
• MMS costs more. A group MMS is billed as MMS, even if all you send is text. For when the extra cost is worth paying, see SMS vs MMS.

One-to-one broadcast avoids all four. It runs on your registered campaign, it scales to your whole list, and it costs plain SMS rates unless you choose to attach an image.

What a one-to-one send actually costs

A one-to-one send is billed by the segment. A segment is 160 GSM-7 characters, and longer messages split into 153-character parts. An emoji or other non-GSM character switches the message to unicode, which cuts the segment to 70 characters (67 per part in a multipart message).

Worked example 1: a plain schedule notice. Assume 400 contacts and a 150-character message with no emoji. That is 1 segment each.

• 400 × 1 segment = 400 segments
• 400 × $0.0075 = $3.00 at the Standard rate
• Plus 400 × $0.0045 carrier fee

Worked example 2: the same list with an emoji. Now assume a 175-character promo that includes an emoji. That is 3 unicode segments each.

• 400 × 3 = 1,200 segments
• 1,200 × $0.0075 = $9.00
• Plus 1,200 × $0.0045 carrier fee

The emoji tripled the bill. Removing it would bring the message back to 2 GSM-7 segments.

Some notes on these figures:

• Replies are billed like sent texts, at the per-segment rate plus the carrier fee.
• The figures exclude the optional compliance surcharge. DNC/litigator scrubbing and landline validation are each $0.003 extra per segment when switched on, and both are off by default.
• Ready swaps curly quotes, long dashes and ellipses for plain characters before sending, so those don't change your segment count. Emoji do.
• The first 20 texts are free one-to-one sends. A campaign is paid from its first text, and to send any text you need a card and a number ($2 a month, the first month charged when you get it).

If you're sending from your own software, the bulk endpoint is the API version of the same idea. POST /v1/messages/bulk takes up to 100 recipients per call, and each recipient gets their own private message. The bulk messages docs cover batching for larger lists.

Side-by-side comparison

When a group thread is genuinely fine

Group threads are the right tool in a few cases:

• Small, known groups who already talk to each other. Examples: a contractor coordinating with a homeowner couple, or a coach updating two parents about one kid. These people want to see each other's replies.
• Internal team coordination. Staff who already share numbers can use a group thread. It's a collaboration tool, not a customer channel.
• Customer-started groups. If a customer adds your business line to a group conversation they created, answering in that thread is normal. On a Ready blue line, which sends as iMessage, group chats land in the same inbox thread as your SMS conversations, so your team still sees them.

The rule of thumb: if everyone in the thread already knows each other and wants to hear each other's replies, a group thread is fine. If you're the only connection between them, send one-to-one.

Consent applies either way

Choosing one-to-one broadcast doesn't replace consent. SMS should go to people who opted in or who have already replied to you. Cold outreach belongs on the phone or in the mail. On Ready:

• Each bulk send and each API send that sets consent_attested records the sender's opt-in attestation: who sent it, to how many people, and when. That is an audit trail of your sends. It is not a per-contact consent record. Store each recipient's opt-in time, wording and page URL in your own system.
• Quiet hours hold messages that would arrive outside permitted local hours for the recipient's area. Campaigns, drip campaigns and automations wait up to 24 hours for the window; a one-to-one or API text is held only if the window opens within 6 hours, otherwise it is refused with 409 QUIET_HOURS_BLOCK and must be resent; a one-to-one reply to someone who texted you in the last 24 hours goes out at any hour.

These features reduce risk. Compliance is still the sender's responsibility. For the full send workflow, see how to send a mass text to customers the right way.

The practical takeaway

For announcements, reminders, promos and alerts, send one-to-one. It keeps numbers private, routes replies only to you, handles STOP cleanly, runs on your registered campaign, and is billed as plain SMS segments you can calculate in advance. Save group threads for small groups who already know each other.

If you want to test it, sign up and use your 20 free one-to-one texts before you register. Most approvals take 2 to 7 days. Once your registration is through, your first campaign goes out as private, individual messages.