Spain's 400 prefix is now in force: what your contact center must change

Some dates get circled in red in a contact center, and this one has arrived: October 2026. Since this month, every commercial call in Spain must come from a nine-digit number starting with 400. That's the Resolution of 14 April 2026, published in the BOE two days later as part of the government's anti-scam plan — and its six-month transition period is now over. The fine print isn't fine at all: carriers block non-compliant commercial traffic.

This isn't a fine that might come. It's a service cutoff. If your operation runs outbound sales, renewals or surveys for commercial purposes in Spain, this affects you now.

What the rule says, without the legalese

Three things, basically. One: the 400 range is reserved exclusively for commercial calls. They're one-way numbers — the customer can't call back, a lock designed against callback fraud. Customer service still lives on 800 and 900, which do work both ways.

Two: once the six-month transition period is over, carriers are required to block whatever isn't compliant. Three: telemarketing from mobiles and ordinary geographic numbers is definitively over. The March 2025 anti-fraud order had already banned the first; the 400 finishes off the second.

It's worth recalling the framework this all fits into, the SAC law: consents that expire after two years if not renewed, and contracts that are void if closed on a call without prior consent. The regulator's message is consistent from start to finish.

The part nobody mentions: answer rates will drop

Let's be honest. A number starting with 400 tells the customer "this is a commercial call" before they even pick up. That's by design. Cold outbound, the kind that lived on the element of surprise, is going to hurt — and the operations that survive will be the ones that call with real consent, at the right time, with something that genuinely matters to whoever answers.

And the other important calls? They'll move to where the customer does recognize who's speaking. That's where WhatsApp verified calls come in: company name and Meta badge on screen, instead of a prefix that invites people not to answer.

The adaptation plan, in short

First, audit your outbound flows and split them with a scalpel: what's commercial (move to 400), what's service or account management (stays on 800/900). A misclassified campaign today is a blocked campaign. Second, if you don't have it yet, request 400 numbering from your carrier or platform without delay — requests are piling up. Third, configure the dialer so outbound identity depends on traffic type, with rules that prevent any crossover. And fourth, reinforce verified-identity channels for what cold calling will stop delivering.

At Vocalcom, the predictive dialer manages outbound identity and number reputation per campaign, and the platform moves the contact to WhatsApp when the call doesn't connect. A rule changing the channel doesn't mean it changes the result.