Last month, De La Rue, the world’s largest currency maker, sent a letter to the central bank complaining that it was owed $71 million and would inform its shareholders if the money were not forthcoming. The letter was leaked to a Venezuelan news website and confirmed by Bloomberg News.

“It’s an unprecedented case in history that a country with such high inflation cannot get new bills,” said Jose Guerra, an opposition law maker and former director of economic research at the central bank. Late last year, the central bank ordered more than 10 billion bank notes, surpassing the 7.6 billion the U.S. Federal Reserve requested this year for an economy many times the size of Venezuela’s.

…While the cash was still arriving — at times, multiple planeloads a day — authorities set their sights on the year ahead. In late 2015, the central bank more than tripled its original order, offering tenders for some 10.2 billion bank notes, according to industry sources.

But currency companies were worried. According to company documents, De La Rue began experiencing delays in payment as early as June. Similarly, the bank was slow to pay Giesecke & Devrient and Oberthur Fiduciaire. So when the tender was offered, the government only received about 3.3 billion in bids, bank documents show.