How are mobile check deposits accepted by banks if they never even get to see them up close?

Question

I always deposit my checks and the money is usually available the next day, sometimes even the same day. But, what protects these companies from fraud? How do they know the check isn’t a fake?

In:

Answer 1

Essentially they use an ACH system to “cash” the check before you are given the money.

If the check were fraudulent they would know before it is fully deposited into your account.