banBlocks and Bans on WhatsApp: What you need to know

Yes, there is a real possibility that a number can be blocked or banned by WhatsApp — and therefore it is essential to follow best practices.

We created this article to share everything we have learned over the years about how to reduce risks, avoid blocks, and keep your sends operating safely.


Why is WhatsApp so strict about spam?

Think about your daily life: you probably receive dozens of promotional SMS, but almost no promotions via WhatsApp. This happens because WhatsApp was created for personal conversations, and any spam-like behavior is quickly identified and punished.

Also, you have probably noticed: whenever a suspicious message arrives, the app offers options to mark as spam and block the contact.

In other words: WhatsApp does NOT allow spam — and takes it very seriously.


Does quantity matter? Yes. But for whom you send matters even more

Many people believe that blocking happens only because of the volume of messages sent. But the reality is different:

📌 What weighs most is the number of different recipients, especially when there is no natural interaction or prior relationship.

We have clients who send promotions to more than 80 thousand people per day, without blocks. How? By following fundamental best practices, which we share below.


Essential Best Practices to Avoid Blocks

1. Number maturation

Use the number normally in the app before connecting to Z-API.

2. Interact via the app or WhatsApp Web before automating

This reinforces to WhatsApp that the account is legitimate.

3. Encourage replies

Messages that generate interaction are less likely to be marked as spam.

4. Offer an opt-out option

Example: "Type 2 to no longer receive these messages."

5. Complete the profile

Photo, name and description increase credibility.

6. Scan the QR Code after 24 hours of registration

Helps with initial validation.


A client who sends to 80 thousand contacts/day without blocks uses this method:

1. The recipient initiates contact

The person saves the number and sends "I want promotions."

2. Personalization

Each message contains recipient data.

3. Opt-out always available

And removed automatically via webhooks.


Summary of Best Practices

  • Avoid sending messages to those who have not saved your number.

  • Always personalize when possible.

  • Encourage replies.

  • Offer an unsubscribe option.

  • Respect opt-out webhooks.

⚠️ Attention: If 3% of recipients mark your message as spam, the number can be banned.


Bans: What really influences

After four years of tests with WhatsApp Web and API, we identified that factors like IP and ASN have minimal impact.

1. Moments of high moderation

Elections, crises, fake news → general increase in bans.

2. Sensitive content

Words like "PIX", "boleto", "card" increase risk.

3. New numbers sending to many contacts

One of the riskiest behaviors.

4. History of recycled numbers

Reused numbers with bad reputation are banned quickly.

5. Volume of unique recipients

This is the most critical factor.

6. Repetition of patterns among replacement numbers

Same photos, names and messages trigger detection mechanisms.

How to reduce the risk

  • Change photo, name and description.

  • Alter the initial sending pattern.

  • Avoid repeating the behavior of the previous number.


What tests show

  • We have already seen numbers being banned just by connecting the QR Code.

  • In other cases, the block occurred after 10 messages to different contacts.

  • Some segments suffer more impact, mainly financial areas and cold lists.


Conclusion

WhatsApp's algorithm changes constantly. Today, the two most important factors are:

1. Number of different recipients

The more unique contacts → the higher the risk.

2. Message content

Keywords, sending pattern and lack of interaction amplify the risk.

Factors like IP, device or type of integration carry less weight.

The safest approach is to monitor, continuously adjust and maintain healthy sending practices.


Official References – Z-API

For further reading, also consult:

🔗 Blocks and Bans https://developer.z-api.io/tips/blockednumberarrow-up-right

🔗 Blocks and Bans (2025) https://developer.z-api.io/tips/blockednumbernewarrow-up-right

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