From June 2026, WhatsApp will allow its users to interact entirely through a username — with no phone number visible or required. For everyday users, this is a welcome privacy upgrade. For performance marketers who’ve built entire growth engines on top of phone-number-based data flows, it’s a disruption that most teams haven’t even begun to plan for. This article breaks down exactly what’s changing, which parts of your marketing stack are at risk, and what you should do about it before the deadline hits.