Quick summary: Vivo, one of Brazil's major mobile carriers, has rolled out network-level anti-spam filtering. It's also catching legitimate business calls across sectors — including calls made through CloudTalk.

This is happening at the carrier level, it isn't specific to your account, and it doesn't require any technical changes on your end.

Vivo has activated an Anti Spam service (part of "Modo Seguro") across all of its mobile lines in Brazil. It analyzes call behavior directly on the network and blocks numbers it identifies as high-volume or "spam-like" callers — with no setup needed on the recipient's side.

The problem: the criteria used to flag spam are also catching legitimate business calls, including calls made by your team. This isn't unique to Vivo, either — other Brazilian carriers are testing similar filters, so the same pattern may show up on other networks over time.

Our voice infrastructure partners are in contact with Vivo and other Brazilian carriers to better understand the blocking criteria and reduce false positives. We'll update this article as there's concrete progress to share.
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Automatic blocking and filtering have already been reduced by 33% at the partner level since the launch of these new measures in August 2026

If your business has a Brazilian entity with a CNPJ, you can request a review of a blocked number directly through Vivo's unblock form.

One thing worth knowing: the form itself asks for the CPF of the line holder (an individual taxpayer ID), not the CNPJ directly, plus a separate "Name / Corporate Name" field. In practice, this means a business can likely still submit the request using the responsible individual's CPF alongside the company name in that field — even though the process isn't strictly gated on the CNPJ the way it might first appear.

Information the form asks for:

Vivo reviews the request and removes the block if the number is found to comply with its Anti Spam rules.

Is this a CloudTalk-specific issue? No. It's a filter Vivo applies on its own network, affecting calls from any carrier or provider that looks spam-like to its algorithms — it isn't specific to your account or to CloudTalk.

Do I need to change any settings right now? No. No technical action is required on your end.

How long will this take to resolve? There's no confirmed timeline yet. We're tracking progress with our telephony partners and will update this article as things develop.

What if my business doesn't have a Brazilian CNPJ? In that case, contesting a block directly through Vivo's form may not apply to you. Check with your legal or compliance team on what options are available for your situation.