You are not permitted to use a number that will identify the customer.
…Follows the LEI with up to 23 additional characters to identify the covered loan or application, which:
(1) May be letters, numerals, or a combination of letters and numerals;
(2) Must be unique within the financial institution; and
(3) Must not include any information that could be used to directly identify the applicant or borrower; …
2. ULI—privacy. Section 1003.4(a)(1)(i)(B)(3) prohibits a financial institution from including information that could be used to directly identify the applicant or borrower in the identifier that itassigns for the application or covered loan of the applicant or borrower. Information that could be used to directly identify the applicant or borrower includes, but is not limited to, the applicant’s or borrower’s name, date of birth, Social Security number, official government-issued driver’s license or identification number, alien registration number, government passport number, or employer or taxpayer identification number.