The world's biggest economies have backed a global minimum corporation tax. G20 finance ministers from countries like China, Brazil, the US and the UK signed up to the deal.
This builds on the agreement reached at the G7 summit in Cornwall in June. It's difficult to overstate just how important this is.
Campaigners around the world have pushed to fix the current system for decades. At the moment some of the biggest companies in the world get away with paying ultra-low rates of tax. The deal would start to fix this problem.
However, the deal doesn't do much for lower income countries. It's notable that countries like India and Argentina are critical of it. Campaigners are angry that most of the extra money will go to the richest countries.
The agreement came last week, during the same week that the UK government voted to reduce the amount of foreign it gives. The middle of a global health and economic crisis is not the time to be cutting lower income countries off.
It's unfair that politicians are cutting aid with one hand while barring lower income countries from their fair share of tax with the other. It should be in our own interests to help poorer countries fight the pandemic. It's also the right thing to do.