This is why Plaid is so successful, it allows banks/fintech companies to validate that the information on the counterparty account matches what you claim, that it has sufficient amount, name and email matches.
The bank can also decide if he wants to deny an ACH debit or do a manual review of it, for example above a specific amount of if its the 1st ach debit.
Also the clearing days (when you will see money in your bank) will be different depending on different risk factors.
You can read more here about how to mitigate ACH fraud with tools such as Plaid - https://guides.unit.co/fraud-and-disputes/
disclaimer - I am an engineer at Unit.
Plaid also allows its customers to scrape 24 months of transaction data from bank accounts, and gain a constant stream of data about ongoing transactions from the bank account.
It’s a very intrusive data-mining service that should not be trusted with bank account credentials, at-least if you care about data privacy.
Change your bank account password, and you may even see Yodlee (like Plaid) trying to login to your bank account every night to scrape daily transaction data based on some ’bank verification’ you previously gave to some app or 3rd party.
Yeah, place many places where you can pay with ACH require validation that you have access to that account by making small transactions. Plaid will be "instant", but manual ACH will take a few days, even though manual ACH could be the same kind of "instant".
