Why are the UK and US versions of Microsoft Money so different

Financial systems in the US and UK are very different. The UK product is customised to the UK market and vice versa - there is no way that the UK support line could ever support the US product, as they don't have the knowledge of the US financial system, and this is the same for the US support.

The UK Personal Finance Program Manager for Money stated:

Money is the most localised product we do in the UK and no one else dedicates as much resources as we do on producing a UK personal finance product. Word just needs to install a UK dictionary.

Autoroute & Encarta use different content, but the functionality is identical. Money has UK specific functionality that is developed in the UK by UK developers. Yes, the US has features that the UK does not, but the UK also has features that the US does not. Because the UK & US editions work differently, they store different data and so the file format is different.

While it would be possible to make the file format flexible enough to store UK, US, French, Japanese and Rest of World features, this would make the files larger and the program slower. Most customers will probably agree that the files are already large enough.