An earn out agreement is a contractual agreement between the buyer and seller of a business that states that the seller will receive future payment(s). Whether you opt for a lump-sum payment, an installment plan, or an earn-out arrangement, each has its pros and cons.An earnout provision makes the purchase price (typically, some part of it) payable in the future dependent on the buyer's financial performance. What is an Earnout Agreement? ​​An earnout agreement, also referred to as an earn-in or earn-out, is a type of acquisition payment structure.