Interest on extended payments. (a) Tax shown on the return.
Section 118
SEC. 118. Interest on extended payments. (a) Tax shown on the return. — If the time for the payment of the amount determined as the taxes by the donor or by the donee is extended under the authority of subsection (b) of section 116, there shall be collected, as part of such amounts, interest thereon at the rate of six per centum per annum from the date when such payment should have been made if no extension had been granted, until the expiration of the period of the extension. (b) Deficiency. — In case an extension for the payment of a deficiency is granted, there shall be collected, as a part of the taxes, interest on the part of the deficiency the time for payment of which is so extended, at the rate of six per centum per annum for the period of the extension.