If you are managing the book in multiple currencies, take note that only Bank, Accounts Receivable, Accounts Payable and Credit Card account type in QuickBooks can have multiple currencies, the rest of the account such as income, expenses, fixed asset, etc. are all in base currency (home currency).
You get an error of “The currencies of your account and customer/vendor must be the same” in entering bill when a wrong currency has applied to the account. For example, you are supposed to create an expense account which has a base currency by default but set the account type accidentally to bank type with foreign currency tagged. Now, if you use this wrongly created account in “Enter Bill” with a base currency supplier, you will get an error prompt that “The currencies of your account and customer/vendor must be the same”.
You can record a foreign currency supplier bill with a base currency expenses in QuickBooks but not vice versa.