Understanding the seller’s true Net income A deeper understanding of which seller expenses can be added back to the bottom line realistically. The prospective buyer of an auto repair shop for sale in California noticed, while conducting Due Diligence noticed that an office assistant was listed on the payroll. But he'd visited the business as a customer and had never seen anyone working in the office. When inquiring about this, he learned that a "salary" of $1,500 per month was being paid to the seller's sister-in-law, and that she was listed as an office assistant, but didn't actually work at the company. That's an "add-back" and it should be included with net income the seller said.