NY Tax L § 256 (2021)
2021 New York Laws TAX - Tax Article 11 - Tax on Mortgages 256 - Mortgages for Indefinite Amounts or for Contract Obligations.

§ 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.