Your funding source is the external bank account we use to move money in and out of Peak.
It's a bank account that you connect to Peak by securely signing into your bank through our integration with our third party provider Plaid. After the funding source is connected to Peak, any deposit into your Peak account will be pulled from this bank account, and any money withdrawn from Peak will returned to this bank account.
A funding source is required to use Peak. To understand the difference between your funding source and a Transaction source, read this article.