The city could impose its corporate tax on the gain on the sale of a partnership interest in a partnership that did business in New York City. Find info on the process of selling a business and business lawyers with NYC Bar.Use Form 8949 to report sales and exchanges of capital assets. In New York, seller shareholder must recognize gain on the deemed sale of its assets gain taxed as business income and will be New. Both the buyer and seller must complete IRS Form 8594 during the sale to report the sale and purchase of business assets.