Most offers are cash-free and debt-free, assuming a normal level of receivables, inventory, and payables is delivered at closing. That normal level is negotiated, and missing it reduces the final wire.
More detail
The buyer sets a target based on a trailing average, usually twelve months, of the working capital the business needed to operate. At closing, actual working capital is measured against the target and the purchase price adjusts dollar for dollar. Sellers who ran lean on inventory or pushed collections hard in the months before closing can find themselves funding the shortfall out of the proceeds. This is not a trick, it is a standard mechanic, but it is one that surprises first-time sellers regularly. Negotiating the definition and the reference period early, in the letter of intent rather than in the purchase agreement, is worth more than an extra point of multiple in many deals.