We must wait 14 business days before Zelle transactions are returned by the bank. Returns can occur if an individual misses that initial Zelle registration step (via enroll.zellepay.com), an email address is incorrect, an individual's bank chooses not to accept the transaction. If you think there's been an error with a Zelle-related transaction you initiated, please reach out to: AP_SupplierOnboarding@harvard.edu and we will obtain more info for you.