Hi there, @pmac.

Thanks for getting back to us. I'd like to share some additional information about uploading a budget in QuickBooks Desktop.

To answer your question, yes. You can upload the budget for each class by month or one budget per class to to ensure you imported the correct transactions and to avoid issues in the future. 

You can follow the steps provided by my colleague above on how to upload using the .IFF files.

For future reference, you may want to check this article: Create a budget in QuickBooks Desktop.

Please know that you're always welcome to post if you have any other questions about the budget. Wishing you and your business continued success.