The short answer.
A WhatsApp link (wa.me) opens a chat with your number and an optional prefilled message, with no need to save your contact first. Enter your number with the country code, write the first message you want customers to send, then copy the link or download the QR for posters, packaging and ads.
Why every business needs a wa.me link
Customers hate saving numbers. A click-to-chat link drops them straight into a conversation with your business, with the first message already typed. Put it on your Instagram bio, Google Business Profile, website buttons, email signatures and Click-to-WhatsApp ads. The QR version works offline: on counters, menus, standees, product boxes and visiting cards.
Pro tips for higher reply rates
Prefill a message that tells you where the lead came from, for example “Hi! I saw your Diwali offer on Instagram”. Then you instantly know which campaign is working. Keep it under 120 characters, and use a different link for each channel so you can track them separately. When you need broadcasts, chatbots and a team inbox on top, that's where the official WhatsApp Business API comes in.