Hi tim-trimble-circ, thanks for joining the Community.
It isn't possible to import data from an Excel file when creating a budget, figures would need to be entered manually or by using the pre-fill option to auto-fill actual data (once saved, these figures can then be edited). We recommend leaving feedback for this (via the Cog > Feedback in QB) as we appreciate it would be a handy option to have for those who have already prepared budget reports prior to joining QB.