31 CFR § 342.5 - Limitations.
(a) Purchases -
(1) Payroll savings plans. Under a payroll savings plan, withholdings for notes could not exceed the ratio of $1.08 for the notes to $1 for the Series E bonds and could not exceed $20.25 per weekly pay period, or $40.50 per biweekly or semi-monthly pay period, or $81 per monthly pay period.
(2) Others. In combination purchases of notes and Series E bonds, other than under a payroll savings plan, purchases of notes could not exceed $350 (face amount) a quarter, and in no event could the annual limitation of $1,350 (face amount) be exceeded.
(b) Holdings. The face amount of savings notes originally issued to any one person during any one calendar year, was limited to $1,350.