Bank Code Bank Code Verification 1 — Questions and Answers
Question 1: What mathematical formula is used to validate an ABA routing number?
- 3(d1+d4+d7) + 7(d2+d5+d8) + 1(d3+d6+d9) must be divisible by 10 (Correct answer)
- The sum of all nine digits must equal 100
- Each digit must be less than 5 and the total must be even
- The product of alternate digits must equal the remaining digits
Correct answer: 3(d1+d4+d7) + 7(d2+d5+d8) + 1(d3+d6+d9) must be divisible by 10
The ABA checksum algorithm multiplies each digit by 3, 7, or 1 in a repeating pattern and requires the total to be divisible by 10.
Question 2: How many digits make up a standard US ABA routing number?
- 7
- 8
- 9 (Correct answer)
- 10
Correct answer: 9
ABA routing numbers always consist of exactly 9 digits, with the last digit serving as the check digit.
Question 3: What is the primary purpose of the check digit in an ABA routing number?
- To identify the bank's home state
- To detect data-entry or transmission errors (Correct answer)
- To indicate the type of account associated with the bank
- To encode the bank's Federal Reserve membership date
Correct answer: To detect data-entry or transmission errors
The check digit (9th digit) allows any system receiving the routing number to quickly validate it and catch transcription or transmission errors.
Question 4: What do the first four digits of an ABA routing number represent?
- The bank's FDIC certificate number
- The account holder's region code
- The Federal Reserve routing symbol (Correct answer)
- The year the bank was chartered
Correct answer: The Federal Reserve routing symbol
The first four digits form the Federal Reserve routing symbol, which identifies the Federal Reserve district and processing center for the bank.
Question 5: When a routing number fails ABA checksum validation, what should the receiving system do?
- Process the transaction with a warning logged
- Automatically correct the routing number and proceed
- Reject or flag the transaction for manual review (Correct answer)
- Charge the sender a validation fee before processing
Correct answer: Reject or flag the transaction for manual review
A failed checksum means the routing number is likely incorrect, so the transaction should be rejected or sent to manual review to prevent misdirected funds.
Question 6: Which digits in an ABA routing number identify the specific financial institution?
- Digits 1–4
- Digits 5–8 (Correct answer)
- Digits 3–7
- Digits 6–9
Correct answer: Digits 5–8
Digits 5 through 8 make up the ABA institution identifier, uniquely distinguishing one bank from another within the Federal Reserve system.
Question 7: Which organization is responsible for assigning and maintaining ABA routing numbers?
- The Federal Deposit Insurance Corporation (FDIC)
- The Office of the Comptroller of the Currency (OCC)
- The American Bankers Association (ABA) (Correct answer)
- The Consumer Financial Protection Bureau (CFPB)
Correct answer: The American Bankers Association (ABA)
The American Bankers Association created and continues to administer the routing transit number system used for US bank identification.
Bank Code Bank Code Verification 1
What mathematical formula is used to validate an ABA routing number?