A: Treatment of software payments can be complicated and all facts and circumstances must be reviewed before making determination as to how to tax a payment of such type.
Generally, if the title passes to the buyer, this is sales of software.
If the title remains with the owner but the rights transferred to the payer on the software include (i) The right to make copies of the computer program for purposes of distribution to the public by sale or other transfer of ownership, or by rental, lease or lending; (ii) The right to prepare derivative computer programs based upon the copyrighted computer program; (iii) The right to make a public performance of the computer program; or (iv) The right to publicly display the computer program - this would qualify the payment as royalty payment. In all other cases where the title does not pass to the payer and the transferred rights do not include any of the above - this is a regular lease payments which is business income to the recipient.
For more information please see, https://www.law.cornell.edu/cfr/text/26/1.861-18