Add a proof of deletion step to the customer offboarding checklist

When a customer leaves, copies of its data remain in backups, tickets, and documentation. Data that is kept without a reason breaches the agreement and the GDPR, and it makes any later breach worse.

Measures

The offboarding checklist lists every place where customer data lives and who removes it, and the account manager asks the customer to confirm. The proof of deletion is stored with the record of the customer.