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 behavior similar to spam is quickly identified and punished.
Also, you may have 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 who you send to matters even more
Many people believe that blocks happen only because of the volume of messages sent. But the reality is different:
📌 What weighs the most is the number of different recipients, especially when there is no natural interaction or prior connection.
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 stop receiving these messages."
5. Complete the profile
Photo, name and description increase credibility.
6. Scan the QR Code after 24 hours of registration
It helps with initial validation.
Recommended sending method (real case)
A client who sends to 80k 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 may be banned.
Bans: What really influences them
After four years of testing with WhatsApp Web and API, we identified that factors like IP and ASN have minimal impact.
1. Periods of high moderation
Elections, crises, fake news → general increase in bans.
2. Sensitive content
Words like “PIX”, “boleto”, “card” increase the risk.
3. New numbers sending to many contacts
One of the riskiest behaviors.
4. History of recycled numbers
Reused numbers with bad reputations are banned quickly.
5. Volume of unique recipients
This is the most critical factor.
6. Repetition of patterns among replacement numbers
Identical 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 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 increase 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.
