Skint is informal slang, used more in casual conversation than in formal writing or speeches. Can't buy that game yet, I'm totally skint until payday.
Pro Tip 2/3
British Use
Skint is predominantly used in the UK, so non-British English speakers might not be familiar with it. The tourists seemed confused when I said I was skint.
Pro Tip 3/3
Not for Business
Avoid using 'skint' in professional or business situations, as it's too casual and could be seen as unprofessional. We've had a tough quarter, but 'we're skint' is not suitable for the financial report.