How to send opt-in bulk notifications on WhatsApp

What is a WhatsApp bulk notification (broadcast)?

A broadcast means delivering the same information to many customers at once, proactively — that is, you inform the customer before they even ask. The typical examples are clear: a tracking code with a 'your order has shipped' notification, an appointment reminder for the next day, news that an out-of-stock item is available again, or an announcement sent to a selected audience. The aim here is not conversation but delivering an expected piece of information on time. The important distinction: these messages go out without waiting for the customer to write first, so they can only be sent to people who have agreed to receive them.

Why must it be opt-in?

WhatsApp is a permission-based channel. Before you can send a customer a proactive notification, they must have given explicit consent beforehand; sending in bulk without permission breaks the core rule of the system. This has two concrete consequences. First, on the platform side: unsolicited bulk messages violate WhatsApp's policies, and customer complaints and spam flags can quickly lead to your number being restricted or your account being suspended — meaning you lose the channel entirely. Second, on the legal side: in Germany in particular, an unsolicited commercial message is treated as unlawful marketing under the Act Against Unfair Competition (UWG), and sending it without prior explicit consent (opt-in) is not permitted; this carries the risk of a formal warning letter and legal claims. In short, an unsolicited blast is not just an ethical question but, more often than not, a path that does not work and puts your channel and reputation at risk. An opt-in list may look smaller, but it is the list that actually arrives and gets read.

How do the WhatsApp Business API and approved template messages work?

For individual conversations the WhatsApp Business app is enough; but to send proactive notifications to an opt-in list, the WhatsApp Business API and approved template messages come into play. A template is a predefined message pattern you can send without the customer writing first, and which WhatsApp must approve. It contains variables; in the template 'Your order is on its way: [tracking code]', for instance, the field in brackets is filled in separately for each customer. You first submit the template with its category and text for approval; once approved, you can send it in bulk to people with an opt-in. This structure is deliberate: an approved template with variables ensures the purpose of the message is clear and prevents unwanted free-form advertising. You cannot send an arbitrary, unapproved text in bulk — the system does not allow it.

How do you send an opt-in broadcast step by step?

The right order makes the process both compliant and sustainable. First you collect consent: through a checkbox on your site, an opt-in offered during checkout or a conversation the customer starts themselves, you gather those who want to receive notifications — and it matters to keep a record of who consented to what. Next you organise your list and split it into meaningful groups; for example a shipping notification goes only to buyers and a reminder only to people with an appointment. Then you prepare the template for the message and submit it for approval, placing variables such as the tracking code or appointment time into the pattern. In the final step you send the approved template to the right group and watch the result: did it arrive, was it read, did a reply come back? Incoming replies start a conversation; handling those is no longer notification but customer service.

1. 1

   Collect opt-in

   Through a clear step, gather those who want to receive notifications; keep a record of who consented to what.

2. 2

   List and segment

   Split your list into meaningful groups; for example send the shipping notification only to buyers and the reminder only to people with an appointment.

3. 3

   Prepare and approve the template

   Prepare the message template with variables such as the tracking code or appointment time and submit it for approval.

4. 4

   Send and measure

   Send the approved template to the right group; watch whether it arrived, was read and drew a reply.

Which messages can you send?

Messages fall broadly into two types with different rules. First, informational (transactional) messages: notifications the customer expects and that are tied to a transaction — order confirmation, shipping status, appointment reminder or payment information. Because they benefit the customer, they are the most natural use of an opt-in list. Second, marketing messages: promotional content such as campaigns, discounts or new-product announcements. You can send these too, but only to people who have explicitly consented to marketing and under stricter rules; frequent, irrelevant or excessive promotion increases the risk of complaints and channel loss. A good balance puts useful information at the centre and keeps marketing measured. This page covers outgoing (proactive) notifications; answering incoming customer questions is a separate topic, for which you can see our WhatsApp customer service guide.

What determines the cost?

There is no fixed 'broadcast price'; cost is shaped by several factors. First, the country: the sending fee varies with the customer's country. Second, the message type: informational (transactional) and marketing messages are handled in different categories and priced differently. Third, the volume: how many people you reach and how often directly affects the total cost. You should also know that pricing works on a session basis: communication within an opened conversation window is assessed over that window rather than per individual message. So a realistic cost emerges not from a ready-made price list but once these factors are clear; the more precisely you define whom you reach, with what type of message and how often, the more predictable the budget becomes.