I purchased a tool for my business from another country, in a different currency and GST rate - how can I add this expense to my quickbooks?

Hi there,

Making sure your transactions are recorded correctly is a good exercise for preventing errors in your books. 

I recommend contacting an accounting professional to get more info on this. If you're not in contact with one, I encourage you to search for one on our website using this link here. Doing this will help prevent any future discrepancies. Let me know if you have other questions. I'm here to help.