Transparency is important, especially when it comes to funding. As the [Extinction Rebellion] movement grows internationally, everyone should be able to know at all times how much has been raised at the global level and how is the money used to develop the movement. First, I'll share our experience at XR Belgium, then I'll share a proposal for the movement in general.
We are using Open Collective. See https://opencollective.com/XR-Belgium
People can donate money online or by bank transfer. Every time anyone needs money (for supplies and material, renting a place for our general assemblies, etc.), they simply submit the expense or the invoice of the vendor to the collective. All expenses are public and transparent (see https://opencollective.com/XR-belgium/expenses).