3.6.3. Six-Year Records
If FINRA or Exchange Act rules do not specify a time period for a specific book or record, it should be kept at least six years.
FINRA Rule 4511
Records associated with blotters, ledgers, securities, and customer accounts must be retained for six years. These items may be defined as follows.
Blotters. These are daily records containing itemized reports of all purchases and sales of securities and receipts, deliveries of certificates and receipts, disbursements of cash, and all other debits and credits.
General ledger. This ledger includes