Check fraud & ACH return guides.
Practical, plain-English guides for the people who actually handle the checks and build the ACH files — check cashers, ACH originators, and payment processors.
How to verify a check before you cash or deposit it
A step-by-step process for validating the routing number, the bank, the account and the person in front of you — in the time it takes to count out the cash.
Read the guide → Check fraud12 check fraud red flags every teller and cashier should know
The physical, printed and behavioral signs that a check is counterfeit, altered or stolen — and how to confirm each one in seconds.
Read the guide → ACH returnsACH return codes explained: R01, R02, R03, R04, R10 and R29
What each return code means, how long the RDFI has to send it back, and which ones you can prevent before the file goes out.
Read the guide → ACH returnsHow to reduce ACH return rates and stay under Nacha thresholds
Nacha's 0.5% / 3% / 15% return-rate limits, how to calculate yours, and the pre-submission controls that bring it down.
Read the guide → Check verificationRouting number validation: how to verify a routing number on a check
What the nine digits mean, how the ABA checksum works, why the FedACH directory matters, and what validation can and can't tell you.
Read the guide → ProductSee how Check EFI runs all of this automatically
OCR, routing validation, fraud scoring, OFAC, address and ID match — one decision in about ten seconds.
How it works →Fresh posts on check fraud, ACH and payments.
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