New York Consolidated Laws, Tax Law - TAX § 1404. Liability for tax

(a) The real estate transfer tax imposed pursuant to section fourteen hundred two of this article shall be paid by the grantor and such tax shall not be payable, directly or indirectly, by the grantee except as provided in a contract between grantor and grantee or as otherwise provided in this section.  If the grantor has failed to pay the tax imposed by this article at the time required by section fourteen hundred ten of this article or if the grantor is exempt from such tax, the grantee shall have the duty to pay the tax.  Where the grantee has the duty to pay the tax because the grantor has failed to pay, such tax shall be the joint and several liability of the grantor and the grantee;  provided that in the event of such failure, the grantee shall have a cause of action against the grantor for recovery of payment of such tax, interest and penalties by the grantee.  In the case of a conveyance of residential real property as defined in subdivision (a) of section fourteen hundred two-a of this article, if the tax imposed by this article is paid by the grantee pursuant to a contract between the grantor and the grantee, the amount of such tax shall be excluded from the calculation of consideration subject to tax under this article.

(b) For the purpose of the proper administration of this article and to prevent evasion of the tax hereby imposed, it shall be presumed that all conveyances are taxable.  Where the consideration includes property other than money, it shall be presumed that the consideration is the fair market value of the real property or interest therein.  These presumptions shall prevail until the contrary is proven, and the burden of proving the contrary shall be on the person liable for payment of the tax.