How to Send Bulk WhatsApp Messages

Practical guidance for effective mass communication on the messenger.

Why do more companies research ways to send bulk messages on WhatsApp efficiently? The messaging app has long moved from a casual app for friends and family to a capable business tool. For example, the majority of incoming messages are read by recipients within 5 minutes, with average open rates exceeding 90% — a stark contrast to email, which was once created as a dedicated business tool.

Since WhatsApp enforces strict rules on mass messaging, brands intending to send bulk messages need to know the practices to keep their business number safe from bans.

In the article, we’re going to explore how WhatsApp bulk messages work, methods to send them and the step-by-step process, along with best practices and pitfalls to avoid.

What WhatsApp bulk messaging is

Why use WhatsApp for bulk messaging

Sending WhatsApp messages to multiple contacts at once can help brands achieve several business goals.

• Marketing and sales: announcements of promotions, sales, new collections, and personalized special offers.
• Service and transactional notifications: reminders about an upcoming conference or webinar, mass order confirmations, or delivery information.
• Reactivating and retaining the customer base: collecting feedback (NPS), birthday greetings, reminders about an abandoned cart.

Methods for sending bulk messages on WhatsApp

There are two main ways to send WhatsApp bulk messages. For companies, the choice mainly depends on the customer base size and customization requirements.

Broadcasts on WhatsApp Business App

Designed specifically for small enterprises, the WhatsApp Business app is a free mobile and desktop solution featuring built-in Broadcast Lists. A company can create a list of contacts and send a single message to them all at once.

While affordable and convenient, this method comes with several limitations:

• Recipient limit: a single broadcast list cannot exceed 256 contacts.
• The number saved in contacts: the broadcast will only be delivered to recipients who have the company’s number saved in their phone’s address book.
• No extra features: WhatsApp Business app lacks automation, delivery analytics, and personalization capabilities (such as automatically inserting a customer’s first name).

WhatsApp Business Platform (WhatsApp Business API)

For mid-market companies and large enterprises, there is the official WhatsApp Business API, also called WhatsApp Business Platform or WABA. The platform integrates directly into an existing CRM, messaging platform, or customer service software, either via an official Business Solution Provider (BSP) or proprietary Cloud API.

After the integration, a user uploads the company’s customer database into the integrated CRM or broadcast tool, submits a message template for moderation, and launches the campaign.

Compared to WhatsApp Business app, this approach has multiple advantages:

• Universal delivery: Messages reliably reach the audience regardless of whether they have the company’s number saved in their contacts.
• Tiered scalability: Sending limits start at 1,000 unique conversations per day. As the company’s phone number builds a positive trust score, the capacity automatically scales to 10,000, 100,000, and an unlimited tier.
• Interactivity & personalization: the platform supports rich media, documents, and interactive buttons (quick replies, website links, or direct calls). It also features dynamic variables to personalize each message with a client name, order number, loyalty point balance, and so on.
• Advanced automation: the API can be connected to AI chatbots and complex automated sales funnels for efficient inquiry processing on WhatsApp.

There are plenty of unofficial WhatsApp bulk senders and third-party tools for bypassing API integration. Relying on them for communication with a legitimate customer database is a huge risk. WhatsApp’s machine learning algorithms are capable of detecting unauthorized bulk messaging behavior, which often results in a permanent, irreversible ban on a business phone number after just a few dozen automated messages.

How to send bulk WhatsApp Messages step-by-step

Let's walk through the setup process using both the WhatsApp Business App and the official API.

WhatsApp Business App: for small contact lists

1. Set up the app. Download the WhatsApp Business app from the App Store or Google Play and register a dedicated business phone number.
2. Verify address book status. Ensure your clients have saved your business number in their device's contacts. The best way is to actively prompt them to do this during checkout or when signing up for a loyalty program, before sending a broadcast.
3. Create a broadcast list: On Android: tap the More options icon (the three vertical dots in the top right corner), then select New broadcast. On iOS (iPhone): go to the Chats tab, tap Broadcast Lists in the top left corner, and then tap New List at the bottom of the screen.
4. Select recipients. Choose contacts from your address book (up to 256 per list) and tap the Checkmark icon (on Android) or Create (on iOS).
5. Draft and send. Type your message into the chat bar, tap the Plus (+) or Paperclip icon to attach any necessary images or files, and tap Send. Each recipient will receive the broadcast in their private chat with your company.

Official WhatsApp Business API: for high-volume campaigns

1. Connect to the API. Register with an official Business Solution Provider (BSP) or directly through Business Manager. Complete the verification process and link a "clean" phone number (one not active on the standard WhatsApp or WhatsApp Business mobile apps).
2. Create and submit a message template. When using the API, you cannot initiate outbound marketing with arbitrary text. Your first contact must always use a pre-approved template. Select a template category (Marketing, Utility, or Authentication). Add a header, draft the body, add interactive buttons, then submit the template for moderation. Approval can take anywhere from a couple of minutes to a few hours.
3. Prepare and segment the audience. Export a customer database from your CRM, either as a CSV/Excel file or via a direct API integration. Ensure all phone numbers are formatted with international country codes. Crucially, the database must include columns that correspond to the template variables (e.g., first name, city, product name).
4. Configure the campaign. Log into your API messaging platform or CRM dashboard. Select your newly approved WhatsApp template, upload your segmented audience list, map the database columns to the corresponding template variables, and set the sending schedule (immediately or at a future time).
5. Launch and monitor. Click Send to start the broadcast. Use your platform's analytics to track delivery metrics in real time, including how many messages were sent, delivered, and read, as well as the click-through rate on your interactive buttons.

Best practices for WhatsApp Business bulk messaging

To make bulk messages on WhatsApp a truly effective instrument for boosting sales and conversions, follow the rules described below.

Obtain a clear opt-in

Send messages only to customers who have given explicit consent to receive notifications. Collect consent at the moments when people are already engaged (checkout, a loyalty sign-up, a lead form) with an unticked checkbox that names WhatsApp and the type of messages ("offers and order updates"). Store the date and source of each opt-in in your CRM so you can prove consent if a question ever arises.

Make it easy to opt-out

Give subscribers a quick way to unsubscribe from marketing messages, such as an "Unsubscribe" button or a STOP command. Opting out should always be easier than reporting your message to WhatsApp, because blocks and reports lower the number's quality rating, which can reduce sending limits or even get the number restricted. Add the opt-out option to the template itself as a quick reply button, and sync it to your CRM immediately so an unsubscribed customer never receives another broadcast later on.

Segment the audience

Do not bulk message the same offer to the whole customer base. Group customers by preferences, purchase history, location, and so on, then send each group an offer that fits its buying profile rather than a generic message. Start with three simple segments, such as new customers, repeat buyers, and lapsed customers (no purchase in 60-90 days). Give each its own offer and compare results before building anything more complex.

Keep it brief

Where possible, keep the message under 500 characters. Nobody enjoys reading long texts in a messaging app, especially when they lack paragraph breaks and formatting. Put the offer and the deadline in the first two lines, use the personalization variable ({{1}}) for the name, and end with a single, clear action. One message should carry one call to action.

Use quick reply buttons

When sending via the API, add interactive buttons with a call to action to encourage engagement. Replies are typically much more frequent when customers can tap a button than when they have to type an answer.

Set up incoming inquiry automation

A successful WhatsApp bulk messaging campaign results in numerous new chats with customers within hours. Use a chatbot to process and qualify inquiries quickly, then route them to human agents, who should also be prepared for a temporary spike in message volume.

Schedule the campaign for a time when your team is online, and send it in batches rather than all at once so replies arrive at a manageable pace. Set up a short auto-reply for after-hours responses, and make sure the bot can hand over the dialogue to a person at any point.

Mistakes to avoid and WhatsApp restrictions

WhatsApp’s parent company maintains strict rules against spamming using bulk messaging. If a company doesn’t adhere to the app’s policy, it is very likely to face contact limits downgrades and even account suspension.

• Missing the 24-hour window. A brand can message a customer within 24 hours after receiving their last message. Otherwise, messaging them can only be done via paid pre-approved template messages.
• Forgetting about messaging tiers. The initial limit for a WhatsApp Business account is 1000 chats per day, which can be increased by sending mass messaging campaigns without any complaints from recipients.
• Neglecting number quality rating. Every number has a quality indicator, which is impacted each time a message sent from it is marked as spam or gets blocked. A very low rating leads to full suspension of bulk messaging features.
• Marketing prohibited items or services. WhatsApp policy prohibits using messages to market alcohol, tobacco, weapons, drugs, gambling, adult entertainment, and certain financial instruments.
• Buying customer bases. Sending WhatsApp bulk messaging to people who have never heard about your brand is a sure way to destroy the number’s rating overnight.
• Sending occasional ‘blanket’ broadcasts to an old base. If you have a 3-year-old customer base and decided to send them the first bulk messaging campaign, such activity is likely to cause multiple blockings of the number. Reactivate the old base gradually.
• Offering no real value. A dull marketing message without any unique selling point is unlikely to work well, since the majority of customers receive tens of similar messages each day.

Practical use cases for WhatsApp bulk campaigns

Here’s how businesses across different industries use WhatsApp bulk campaigns to increase revenue, re-engage customers, and improve retention.

Promote new arrivals

Use case: send targeted campaigns to customers based on their purchase history, interests, or previous interactions. For example, a fashion retailer can notify customers about a new collection, seasonal sale, or limited-edition product drop.

Example message:

“Hi, {{name}}! Our new fall collection has just arrived. Since you loved our {{previous season}} collection, we thought you might like these new arrivals, too. Get 15% off your first order with code NEW15 through Sunday.”

[Button: Shop New Arrivals] [Button: View the Sale]

Reactivate inactive customers

Use case: reach out to customers who haven’t visited or booked a service recently. A targeted WhatsApp campaign can offer a relevant incentive to bring them back, such as a special price, complimentary service, or limited-time promotion.

Example message:

“Hi, {{name}}! It’s been a while since your last visit. We’d love to see you again. Book any facial treatment this month and get 15% off your next appointment. Offer valid until {{date}}.”

[Button: Book an Appointment] [Button: View Services]

Drive sign-ups

Use case: promote upcoming webinars, courses, workshops, and other events to relevant customer or subscriber segments. WhatsApp campaigns can be used to announce new programs, share early-bird offers, or remind interested contacts that registration is still open.

Example message:

“Hi, {{name}}! Registration is now open for our upcoming webinar on {{date}}. You’ll learn how to {{details}} and get practical tips from industry experts. Reserve your spot before registration closes.”

[Button: Register Now] [Button: Learn More]

Generate sales conversations

Use case: send targeted campaigns to qualified leads or existing business contacts about new solutions, industry-specific features, webinars, or product demos. Segmenting contacts by company size, industry, or previous interactions can make campaigns more relevant.

Example message:

“Hello, {{name}}! We’ve launched a new solution for teams that helps reduce {{metric}} and automate routine workflows. See how it works in a 15-minute demo with our product team.”

[Button: Book a Demo] [Button: See How It Works]

FAQ

How do I send a message to multiple people at once on WhatsApp?

Broadcast lists available on WhatsApp Business app let you send one message to up to 256 contacts as individual chats, but only people who have saved your number will receive it. Meanwhile, WhatsApp Business Platform (that can be connected to your CRM via communication platforms like Umnico) lets you send approved template messages to thousands of opted-in contacts with no 256-contact limit.

How can I send bulk WhatsApp messages without getting blocked?

WhatsApp restrictions almost always come from spam reports, so the safest approach is to follow the messenger’s policies. Message only people who have opted in, use the official WhatsApp Business API rather than mass-sending from a regular or Business app account, and use pre-approved templates for first contact outside the 24-hour reply window. Keep your quality rating high by segmenting your audience, personalizing messages, and making it easy to opt out.

Can I send WhatsApp bulk messages to contacts who don't have my number saved?

Yes, but only through WhatsApp Business Platform. Unlike broadcast lists, API-based sending doesn't require recipients to save your number. Consent still matters, though: skipping the saving step doesn't mean you can skip permission to send marketing messages to them.

Is it free to send bulk messages on WhatsApp?

Sending from WhatsApp Business app is free but is limited to 256 contacts, while the official API charges per delivered template message, with rates that vary by category (marketing, utility, authentication) and recipient country. So check WhatsApp’s regional current pricing and your provider's rates before planning a campaign.

What happens if I use unofficial WhatsApp bulk senders?

Unofficial tools, such as browser extensions, auto-senders, and apps that automate regular WhatsApp accounts, violate WhatsApp's terms of service, and its systems are built to detect automated behavior. Using them may result in a permanent number ban, which means losing the chat history and customer conversations tied to that number. The official API takes more setup, but it protects your number, customer relationships, and brand's reputation.

Summing things up

Whether you are running a small local shop or a growing enterprise, WhatsApp offers multiple tools for effective two-way brand-customer communication. WhatsApp marketing campaigns boast engagement rates that outperform email campaigns, since the message reaches customers in an app they already check multiple times per day.

Umnico's bulk messaging tool for WhatsApp lets businesses send personalized WhatsApp campaigns to their contact base, with rich media, buttons, links, and number validation, via official API at roughly two-thirds the price of a similar SMS campaign. Sign up for Umnico and use the free trial to launch your first bulk WhatsApp campaign, manage replies, and turn interested contacts into customers.