A taxable asset purchase allows the buyer to "step up," or increase, the tax basis of the acquired assets to reflect the purchase price. An asset purchase agreement (APA) is a legally binding document that details the terms and conditions related to the purchase and sale of a company's assets.Asset purchase agreements can be a useful way to create a new business while leaving unwanted resources and potential issues with the seller. An asset purchase agreement is a legal document used when buying or selling a small business. Read on to understand the basics. Working Capital = Current Assets (cash, accounts receivable, inventory, short term pre-paid expenses, etc.) – Current Liabilities (accounts payable, accrued.