Undebt.it does not directly sync with any banks or credit card companies. However, there are two alternatives that can accomplish this. If you are a YNAB user, you can use Undebt.it+ to sync with your YNAB account to keep your data current.
The other option, which was released in September 2026, is syncing via SimpeFIN. SimpleFIN is a third party financial connection service that allows you connect to over 16,000 financial institutions.