31 C.F.R. § 363.131 What is a TreasuryDirect® certificate of indebtedness?
Title 31 - Money and Finance: Treasury
A TreasuryDirect certificate of indebtedness (certificate of indebtedness) is a security held within your primary or linked account, including a minor account for which you are the custodian, that is issued daily, with a one-day maturity, that automatically rolls over at maturity until you request redemption. A certificate of indebtedness has a minimum purchase amount of one cent. The only purpose of a certificate of indebtedness is to accumulate funds for the purchase of another eligible security in the TreasuryDirect system. A certificate of indebtedness within a minor's account is the property of the minor alone.
Title 31: Money and Finance: Treasury
PART 363—REGULATIONS GOVERNING SECURITIES HELD IN TREASURYDIRECT
Subpart D—Certificate of Indebtedness
§ 363.131 What is a TreasuryDirect

