An international reply coupon – IRC is a type of voucher accepted in multiple countries in exchange for local postage stamps. Upon turning one in, coupon holders get the minimum postage required for airmail weighing up to 20 grams.
Only countries taking part in the Universal Postal Union, or UPU, accept IRCs for postage. The UPU is a wing of the United Nations. It coordinates the delivery of global mail, as well as postal policies among member nations. The UPU is based in Bern, Switzerland. The majority of the world’s countries, as well as Vatican City take part in the UPU. The UPU added South Sudan, its most recent member, in 2011.
International Reply Coupons – IRCs facilitate airmail sent between foreign countries. Many letters request the receiver to reply to the sender. However, especially decades ago, lack of information and fluctuating currency exchange rates made it hard to know how much postage either should apply. The IRCs made this much easier by standardizing both the maximum letter weight and the postage price.
The invention of the IRC took a number of years and got an early start in the days before airmail. The UPU began back in 1875, eventually getting all the agreements in place to introduce IRCs in 1906, just a few years following the first airplane flight by Orville and Wilbur Wright in 1903. It took until 1929 for a larger set of rules governing airmail to take shape. Airmail became popular around by the 1930s, as aircraft grew in popularity, size and cargo capacity. At this time, a large percentage of airline revenue came from airmail, as opposed to revenue seat miles.
Prior to airmail, delivery of letters by ship took weeks to some global destinations, if not more than a month. Airmail reduced this timetable to days. For this reason, most countries charged a premium for airmail letters, and IRCs helped to standardize this price.
Of note is that the UPU’s official language is French. For this reason, airmail sent worldwide sometimes bears the words “par avion, meaning “by plane,” even in some countries that do not primarily speak French.
IRCs essentially made airmail practical. Without them, it was easy for senders to either use too little postage or far too much, thus wasting money.
If there’s a downside, it’s that IRCs work only with letters, as opposed to packages and other mail deliveries. The UPU has some international agreements for these types of shipments, but none are as straightforward or comprehensive as IRCs.