In the states where credit for conservation land donations is transferable, free markets have arisen. Brokers assist landowners with excess credit to contact buyers, and the brokers often handle payments and paperwork to protect the principals, and to ensure that transfers are fully reported to the state tax authorities. The federal and state tax treatment of profits from sale and use of transferable tax credit have been the subject of extensive discussion and the issuance of several guidance documents by the Internal Revenue Service.