Vneshposyltorg checks (previously "certificates" and "vouchers") were a kind of "parallel currency" that existed in the USSR in 1964–1988. They were used to pay wages to Soviet citizens working abroad: primarily specialists employed under USSR construction contracts, as well as specialists (for example, teachers, doctors, and military advisers) working under contracts with foreign state and private institutions (hospitals, universities, etc.), rank-and-file embassy employees, and other persons within the USSR who received fees or transfers in foreign currency.
The main purpose of introducing certificates, and later VPT checks, was the Soviet state's desire to limit foreign-currency wage expenditures for citizens working abroad (especially in capitalist countries, where otherwise employees would withdraw their entire salary in foreign currency and spend it locally), and also to reduce the inflow into the country of private imports of goods from uncontrolled sources. While abroad, part of the overseas workers' salary in foreign currency was voluntarily (but no more than 60%) transferred to an account at Vneshekonombank, from which—either on the spot (usually through the economic adviser at the USSR Embassy) or upon returning to the USSR—they could receive a pre-ordered amount in the form of certificates (later, checks). Some categories of overseas employees of foreign trade organizations and diplomats could also bring into the USSR a limited amount of foreign currency, which they were required to convert into certificates (checks) no later than the установленный deadline; otherwise, their possession of foreign currency was also considered illegal.
Certificates existed in three types: "certificates with a blue stripe"—paid to citizens working in CMEA countries (crediting ratio 1:1); "certificates with a yellow stripe"—paid to overseas workers in countries with non-convertible currency, i.e., in the Third World, for example India, African countries, etc. (ratio 4.6:1); and "stripeless certificates"—paid to those working in countries with freely convertible currency (ratio 4.6:1). Thus, "yellow-striped" and "stripeless" certificates unofficially served as a physical analogue of the условно-account foreign-currency "gold" ruble, performing a quasi-function of "Soviet chervonets."
Certificates and vouchers (later checks) could legally be spent exclusively in a network of special stores, the "Beryozka" shops; in addition, they could be paid as a contribution to a housing construction cooperative, but only at a 1:1 rate to the regular ruble, which was also an additional source of state revenue. The essence of the certificate system was that overseas workers in different countries, with formally comparable salary levels (close to the USSR average), in reality received wages that differed greatly in purchasing power. For example, a Soviet interpreter's salary in India, условно 200 rubles, in fact amounted to 920 rubles in "yellow-striped certificates," while an interpreter's salary, for example in Hungary, equal to 400 rubles in "blue-striped certificates," amounted to the same 400 rubles. In "Beryozka," blue- and yellow-striped certificates could be used to buy not only clothing, carpets, crystal, and other consumer goods produced in CMEA countries, but also cars.
For "stripeless certificates," high-quality imported consumer goods were also sold, including Western audio and video equipment and scarce food products. The difference in the purchasing power of certificates was especially clear in the case of passenger cars:
"Volga" GAZ-21 cost 5,500 rubles in "blue-striped" and only about 1,200 rubles in "stripeless" and "yellow-striped";
"Moskvich" AZLK-408 cost 4,500 rubles in "blue-striped" and only about 980 rubles in "stripeless" and "yellow-striped";
"Zaporozhets" ZAZ-966 cost 3,500 rubles in "blue-striped" and only about 760 rubles in "stripeless" and "yellow-striped".