This recorded live webinar event contains helpful information for new sales tax vendors in New York State (recorded 3-5-20). Capital gains from investments (including proceeds from property sales) are treated as ordinary personal income and are taxed at the same rates.Complete Form. NYC-NOLD-UBTI. LINE 7 - INCOME OR GAIN FROM SALE. You need to file a quarterly withholding tax return and make payments. It helps us determine whether you should report sales tax, use tax, or withholding tax. It helps us determine whether you should report sales tax, use tax, or withholding tax. This is the total of state, county, and city sales tax rates. In order to apply the withholding to the gain, the seller must complete Form NR-AF2 (Affidavit of Seller's Gain) attesting to the amount of the taxable gain.