31 C.F.R. § 515.203

(a) Any transfer after the “effective date” which is in violation of any provision of this part or of any regulation, ruling, instruction, license, or other direction or authorization thereunder and involves any property in which a designated national has or has had an interest since such “effective date” is null and void and shall not be the basis for the assertion or recognition of any interest in or right, remedy, power or privilege with respect to such property.

(b) No transfer before the “effective date” shall be the basis for the assertion or recognition of any right, remedy, power, or privilege with respect to, or interest in, any property in which a designated national has or has had an interest since the “effective date” unless the person with whom such property is held or maintained had written notice of the transfer or by any written evidence had recognized such transfer prior to such “effective date.”

(c) Unless otherwise provided, an appropriate license or other authorization issued by or pursuant to the direction or authorization of the Secretary of the Treasury before, during or after a transfer shall validate such transfer or render it enforceable to the same extent as it would be valid or enforceable but for the provisions of section 5(b) of the Trading With the Enemy Act, as amended, and this part and any ruling, order, regulation, direction or instruction issued hereunder.

(d) Transfers of property which otherwise would be null and void, or unenforceable by virtue of the provisions of this section shall not be deemed to be null and void, or unenforceable pursuant to such provisions, as to any person with whom such property was held or maintained (and as to such person only) in cases in which such person is able to establish each of the following:

(1) Such transfer did not represent a willful violation of the provisions of this part by the person with whom such property was held or maintained;

(2) The person with whom such property was held or maintained did not have reasonable cause to know or suspect, in view of all the facts and circumstances known or available to such person, that such transfer required a license or authorization by or pursuant to the provisions of this part and was not so licensed or authorized or if a license or authorization did purport to cover the transfer, that such license or authorization had been obtained by misrepresentation or the withholding of material facts or was otherwise fraudulently obtained; and

(3) Promptly upon discovery that:

(i) Such transfer was in violation of the provisions of this part or any regulation, ruling, instruction, license or other direction or authorization thereunder, or

(ii) Such transfer was not licensed or authorized by the Secretary of the Treasury, or

(iii) If a license did purport to cover the transfer, such license had been obtained by misrepresentation or the withholding of material facts or was otherwise fraudulently obtained;

(e) Unless licensed or authorized by § 515.504 or otherwise licensed or authorized pursuant to this chapter any attachment, judgment, decree, lien, execution, garnishment, or other judicial process is null and void with respect to any property in which on or since the “effective date” there existed the interest of a designated foreign country or national thereof.

(f) For the purpose of this section the term property includes gold, silver, bullion, currency, coin, credit, securities (as that term is defined in section 2(1) of the Securities Act of 1933, as amended), bills of exchange, notes, drafts, acceptances, checks, letters of credit, book credits, debts, claims, contracts, negotiable documents of title, mortgages, liens, annuities, insurance policies, options and futures in commodities, and evidences of any of the foregoing. The term property shall not, except to the extent indicated, be deemed to include chattels or real property.