Every banknote has an ending. After years of circulation, the edges fray, the ink fades, and the note loses its crispness. Central banks then face a crucial question: what to do with the mountains of old notes withdrawn from circulation each year? For decades, the answer was incineration. Today, sustainability demands more.
Cotton-based notes are relatively straightforward to recycle. Once shredded, the fibres can be repurposed into products such as roof tiles, insulation, or stationery. The Bank of England, for instance, has supplied shredded notes to farms, where they are mixed with compost. But the volume is vast: in 2021 alone, the UK withdrew over 200 million paper notes. Scaling up recycling to handle such tonnage consistently remains a logistical challenge.
Polymer substrates complicate disposal. Their durability—an asset in circulation—becomes a burden at the end of life. Incineration was the default for years, but it negates the ecological advantage of polymer’s long lifespan. Recycling into pellets for plastic products is now expanding, with Canada and Nigeria leading the way. These pellets are used in items ranging from garden furniture to drainage piping. The issue is infrastructure: not all regions have facilities capable of processing polymer waste securely and efficiently.
Security is another constraint. Withdrawn notes cannot simply be thrown into municipal recycling streams; they must be destroyed in controlled conditions to prevent misuse. This requirement raises costs and slows experimentation. Partnerships with trusted recycling companies, operating under strict contracts, are one solution.
Innovation is pushing boundaries. Some researchers are developing chemical recycling techniques to break down polymer substrates into their base monomers, which can be reused in high-quality applications. Others are experimenting with hybrid solutions that combine cotton and polymer in ways that allow easier separation at end-of-life.
Public perception matters too. Citizens expect their money, even when obsolete, to be treated responsibly. Announcements about greener disposal programmes—like turning shredded notes into public park benches—carry symbolic weight, reinforcing trust in institutions. The story of what happens to old notes can itself become a form of communication about sustainability.
In the long run, the goal is circularity. Instead of a linear journey from print to destruction, the industry must design systems where materials are continually repurposed. The ICA’s role is to highlight these efforts, set standards for secure recycling, and encourage collaboration between central banks, suppliers, and recyclers. A world where every withdrawn note finds a second life is not just possible—it is already being built.
