§ 256. Mortgages for indefinite amounts or for contract obligations.
If the principal indebtedness secured or which by any contingency may be
secured by a mortgage is not determinable from the terms of the
mortgage, or if a mortgage is given to secure the performance by the
mortgagor or any other person of a contract obligation other than the
payment of a specific sum of money and the maximum amount secured or
which by any contingency may be secured by the mortgage is not expressed
therein, such mortgage shall be taxable under section two hundred and
fifty-three of this chapter upon the value of the property covered by
the mortgage, which shall be determined by the recording officer to whom
such mortgage is presented for record, unless at the time of presenting
such mortgage for record the owner thereof shall file with the recording
officer a sworn statement of the maximum amount secured or which under
any contingency may be secured by the mortgage. If such maximum amount
is expressed in the mortgage or in a sworn statement filed as required
by this section, such amount shall be the basis for assessing the tax
imposed by this article. A statement filed by the owner of a mortgage
pursuant to this section shall thereafter at all times be binding upon
and conclusive against such owner, the holders of any bonds or
obligations secured by such mortgage and all persons claiming through
the mortgagee any interest in the mortgage or the mortgaged premises. If
the maximum amount secured or which by any contingency may be secured by
the mortgage is not expressed in the mortgage or in a sworn statement as
authorized by this section, the recording officer at the time such
mortgage is offered for record may require the mortgagor or mortgagee to
furnish him with proofs as to such facts as he deems necessary for the
purpose of computing the value of the property covered by the mortgage
and such proofs shall include an affidavit of appraisal of the value of
the property made by at least two competent, disinterested persons and
shall be preserved in his office. His determination and copies of the
proofs as to the basis for computing the tax on such mortgage shall be
forwarded to and subject to review by the state tax commission. Such
mortgage shall not be recorded until the statement is filed or the
proofs are furnished as required by this article.

Whenever any such mortgage shall have been recorded without the
payment of the tax as herein provided, and it shall thereafter be
determined by the tax commission, after an opportunity to be heard by
the parties in interest, that the failure to pay such tax was due to an
honest misconception on the part of the recording officer or the owner
of the instrument as to the nature of such instrument and its taxability
under this article, the tax commission may make an order permitting the
recording officer to file the aforesaid statement nunc pro tunc as of
the date of the recording of the mortgage. The payment of the tax may be
made on the basis of such statement with interest thereon at the rate of
six per centum per annum as provided in section two hundred and
fifty-eight of this article.