31 CFR §535.508

1. (a)Any payment or transfer of credit, including any payment or transfer by any U.S.-owned or controlled foreign firm or branch to a blocked account in a domestic bank in the name of Iran or any Iranian entity is hereby authorized: Provided, Such payment or transfer shall not be made from any blocked account if such payment or transfer represents, directly or indirectly, a transfer of the interest of Iran or an Iranian entity to any other country or person.
2. (b)This section does not authorize:
   1. (1)Any payment or transfer to any blocked account held in a name other than that of Iran or the Iranian entity who is the ultimate beneficiary of such payment or transfer; or
   2. (2)Any foreign exchange transaction including, but not by way of limitation, any transfer of credit, or payment of an obligation, expressed in terms of the currency of any foreign country.
3. (c)This section does not authorize any payment or transfer of credit comprising an integral part of a transaction which cannot be effected without the subsequent issuance of a further license.
4. (d)This section does not authorize the crediting of the proceeds of the sale of securities held in a blocked account or a sub-account thereof, or the income derived from such securities to a blocked account or sub-account under any name or designation which differs from the name or designation of the specific blocked account or sub-account in which such securities were held.
5. (e)This section does not authorize any payment or transfer from a blocked account in a domestic bank to a blocked account held under any name or designation which differs from the name or designation of the specified blocked account or sub-account from which the payment or transfer is made.