What is soft opt-in under EU law?

Soft opt-in is an exception under EU ePrivacy Directive (implemented into national laws like the UK's PECR) that allows emailing existing customers about similar products without explicit prior consent. The conditions: the contact was collected during a sale or negotiation, you're marketing your own similar products, you gave them the chance to opt out when collecting the address, and you offer easy opt-out in every message.

This isn't blanket permission to email anyone who ever transacted with you. \"Similar products\" is key. If usomeone bought shoes, you can email about other footwear; emailing them about financial services stretches the definition past breaking. The product/service must be genuinely related to what they originally purchased, not just anything your company sells.

Soft opt-in represents a pragmatic middle ground between opt-in requirements and commercial reality. Businesses can maintain customer relationships through email without forcing explicit re-consent after every transaction. But it requires providing opt-out opportunity at collection (not just in emails) and respecting reasonable similarity limits. Soft opt-in is a narrow exception, not a broad license-use it for genuine customer communication about related offerings, not as a loophole for unrestricted marketing.