ANSWER KEY - customer 09 (WRONG copy)
Document: Key Fact Statement (KFS) (KFS_001)
File: 01_key_fact_statement/kfs_customer_09_wrong.pdf (2 pages)
Customer: Kavya Chopra   Lender: Ulmarin Finance (fictional)

Error type: WRONG_ACCOUNT_IDENTIFIER - the account number is wrong.
Page: 1
Field: the "Account No." field in the reference box at the top of the first page
Correct value: FAC_34065E1DE0
Printed value: FAC_34065E1D10

How it can be caught from this customer's documents:
Compare the account number in the reference box with this customer's other documents: the loan agreement, the monthly statement, the fee invoice, the repayment receipt and the NOC print FAC_34065E1DE0. This copy prints FAC_34065E1D10; one character differs. (The EMI schedule, the foreclosure quote and the closure letter of this customer are wrong copies too, each with a different wrong number; only the true number is printed on more than one document.)

Engine record:
  corruption id COR_8505ABEBCB; mode ISOLATED (only this element was changed; nothing else was adjusted to match)
  reference detector rules whose finding names this field, with the full observation set (the documents and the event feed): account_number
  ... and reading only this customer's nine published documents: account_number

Every figure in this pack comes from a simulated ledger; this one was altered on purpose for training and testing.