If the terms of the contract stipulate that guarantee payments (contributions) perform only the function of a means of securing the fulfillment of obligations and in accordance with the terms of the contract are not credited for payment for goods / services, but returned to the recipient of such goods / services, this amount of guarantee payments (contributions) does not increase the tax base of the supplier of goods / services. Tax liabilities by the supplier and tax credit by the buyer upon receipt / transfer of such guarantee payment are not determined.
Source: visnuk.com.ua