Notes for owners · Digital marketing
WhatsApp broadcast lists or the API: how many customers before you need to switch
A plain comparison of WhatsApp broadcast lists and the Business API: who receives what, opt-in, templates and cost, plus five questions that tell you when staying on the app stops working.
The GullySales team · Updated 17 Oct 2026 · 5 min read
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Stay on broadcast lists while one phone and one or two people can answer every reply, and your customers have saved your number. Move to the API when several people must send, when messages must reach people who have not saved your number, when you want automatic replies, or when you need to see who replied to what. Those four matter more than the customer count.
What does a broadcast list actually do?
A broadcast list on the WhatsApp Business app sends one message to many contacts, each of whom receives it as a private chat. They do not see each other. If they reply, the reply lands in your one-to-one chat with them.
Two limits catch owners out. First, it reaches only the contacts who have saved your number, so a buyer who messaged you once and never saved you gets nothing. Second, each list has a cap on its size, which WhatsApp sets and can change, so check the current number in the app rather than trusting any article. You also get little reporting: you can see delivered and read ticks, but not a tidy record of who clicked or replied.
For a shop that sends a new-arrivals message to three hundred regulars, this is fine.
What changes with the API?
The WhatsApp Business API is the version software connects to, through an approved provider. You do not get a phone app; you get a shared inbox, usually in a web screen, which several people can use.
| Question | Broadcast list on the app | The API |
|---|---|---|
| Who can send | One phone, or a few linked devices | Many agents on one number, through software |
| Who receives | Only people who saved your number | Anyone who has agreed to hear from you |
| First message to a stranger | Not allowed through a broadcast | Allowed with their opt-in and an approved template |
| Message wording | Anything you type | Marketing messages, and anything outside the reply window, use approved templates |
| Automatic replies | A basic greeting and away message | Flows, routing, reminders, chatbots |
| Records | Chat history on the phone | Logs, tags and reports in the tool |
| Cost | Your own time and phone | Provider and platform fees apply; get current terms in writing |
Do not decide on cost from a figure you saw elsewhere. Ask each provider for the current price list in writing.
The five questions that tell you when to switch
Answer yes or no. Two yeses are a reason to ask a provider for a demo. Four yeses suggest the app is already costing you enquiries.
- Do two or more people need to reply from the same number at the same time?
- Do you need to message people who have asked for something but have not saved your number, such as form enquiries?
- Do you send the same reminder, for example a fee date, a service due date or an order update, many times a day?
- Can you tell who replied to last week's message without scrolling for ten minutes?
- Has WhatsApp ever restricted your number?
Question one is easy to overlook. A single phone shared between two reception desks produces answers that contradict each other, and nobody knows who promised the discount.
For example: a sweet-and-snack maker in Thrissur
This case is invented. A family business in Thrissur sells banana chips and halwa in boxes. At Onam and Vishu it takes bulk orders from offices and families. The owner keeps a broadcast list of four hundred buyers and sends the festival price list from one phone.
The problem appears in the third year. Some of the buyers had messaged once through the website form and never saved the number. Part of the broadcast went to people who could not receive it, and nobody knew. Meanwhile two relatives were both replying from the same phone, once quoting two different rates for the same box.
The business does not need a chatbot. It opens an API account through a provider, moves enquiries from the form into a shared inbox, and has each person answer under a name. The festival message goes as an approved template to people who ticked the box on the form and to those who said yes on the earlier broadcast. Perhaps two hundred of the four hundred qualify, and the rest stay on the old list and get a call instead, which takes a week of evenings.
This is not a huge business: four hundred customers, three people answering and two sources of enquiries. The second and third facts mattered more than the first.
What should you do before moving?
Export your contacts into a sheet and add a column for how each person agreed to hear from you: a form tick, a reply to your message, or a chat they started. Mark anyone you cannot place as "not sure" and leave them off the first API list. Moving a list without that column is a good way to regret the switch, because you will not be able to show who agreed. Keep the old app number's chats too, and tell regulars the number is not changing, so they do not think your messages are spam.
What the API will not do for you
It will not make people want your message. A weak broadcast becomes a weak template, now with a fee attached. It will not remove the need for consent either: you need a record that each person agreed to be messaged.
If you are not sure you need any of it, the longer comparison is in WhatsApp Business API for small businesses. For repeat orders on the app, see broadcast lists for repeat shoppers.
When to stay where you are
Stay on the app if one person answers everything, your customers have saved your number and you send a few messages a day. Moving early adds fees and a new inbox to learn. Move when a real problem, such as clashing replies, missed enquiries or a restricted number, is already costing you. Write the problem down first, so you can tell afterwards whether the switch fixed it. If it is already costing you, WhatsApp Business API setup covers the account, the number and the provider, and the marketing hub shows where it fits. To weigh it up for your own list, tell us what you need.
