What is “contractual necessity” as a legal basis?

Contractual necessity (GDPR Article 6(1)(b)) allows processing when it's necessary to perform a contract with the data subject or to take steps at their request before entering into a contract. For email marketing, this basis primarily applies to transactional and service communications rather than promotional marketing. When someone purchases a product, the contractual relationship creates a legal basis for sending order confirmations, shipping notifications, and account-related communications necessary to fulfill that purchase.

The key test is necessity-processing must be genuinely required to deliver the contracted service or product. An order confirmation is necessary to contractual performance (the customer needs to know their order was received). A password reset email is necessary when the customer requests account access. However, promotional emails about other products you sell are not "necessary" for contract performance. The ucustomer can receive their purchase without receiving marketing. Thus, contractual necessity rarely justifies marketing emails, only genuinely transactional ones.

When relying on contractual necessity, document the connection between the communication and the contract. What contract does this email support? How is this communication necessary for that contract's performance? Keep the scope narrow-adding promotional content to transactional emails can undermine the contractual necessity basis. Remember that contractual necessity doesn't require consent, but it also doesn't grant permission for unlimited communication. Contractual necessity covers what you must send to fulfill the deal-not what you'd like to send while you have their attention.