If your Delta eCredit is not working it may be due to a billing issue, or a technical error. First, check your Delta eCredit account to make sure the funds are available. Contact Delta directly if there’s an issue, or try another form of payment. If it’s a technical issue, try resetting the payment method, restarting the device, or updating the app. Also, make sure you’re not entering incorrect information or attempting to pay with a closed or expired card. If none of these solutions work, contact Delta or their customer service to resolve the issue.