Sec. 3408. Formal written request

A Government authority may request financial records under section 3402(5) of this title pursuant to a formal written request only if -

(1) no administrative summons or subpena authority reasonably appears to be available to that Government authority to obtain financial records for the purpose for which such records are sought;

(2) the request is authorized by regulations promulgated by the head of the agency or department;

(3) there is reason to believe that the records sought are relevant to a legitimate law enforcement inquiry; and

(4)(A) a copy of the request has been served upon the customer or mailed to his last known address on or before the date on which the request was made to the financial institution together with the following notice which shall state with reasonable specificity the nature of the law enforcement inquiry:

''Records or information concerning your transactions held by the financial institution named in the attached request are being sought by this (agency or department) in accordance with the Right to Financial Privacy Act of 1978 (12 U.S.C. 3401 et seq.) for the following purpose:
''If you desire that such records or information not be made available, you must:

     ''1. Fill out the accompanying motion paper and sworn statement or write one of your own, stating that you are the customer whose records are being requested by the Government and either giving the reasons you believe that the records are not relevant to the legitimate law enforcement inquiry stated in this notice or any other legal basis for objecting to the release of the records.

     ''2. File the motion and statement by mailing or delivering them to the clerk of any one of the following United States District Courts:

     ''3. Serve the Government authority requesting the records by mailing or delivering a copy of your motion and statement to .

     ''4. Be prepared to come to court and present your position in further detail.

     ''5. You do not need to have a lawyer, although you may wish to employ one to represent you and protect your rights. If you do not follow the above procedures, upon the expiration of ten days from the date of service or fourteen days from the date of mailing of this notice, the records or information requested therein may be made available. These records may be transferred to other Government authorities for legitimate law enforcement inquiries, in which event you will be notified after the transfer;'' and

(B) ten days have expired from the date of service or fourteen days from the date of mailing of the notice by the customer and within such time period the customer has not filed a sworn statement and an application to enjoin the Government authority in an appropriate court, or the customer challenge provisions of section 3410 of this title have been complied with.