If your previously created budget or forecast uses imported data, you can update your actuals or budget at any time. First, you'll need to import the updated data in the Task Manager tab, and then within the budget or forecast you can use the Sync Imported Data button found in the upper right-hand corner of the Customise Data tab, to bring through the data you want.
Once the import completes, the data is available for you to sync into your budget or forecast.
Note: If you choose to update budgets, your existing budget values in Spotlight will be overwritten. You should only update budgets if you want to replace the budget values currently held.
Elsewhere in the Help Centre:
Import your data
Select which data to use
Customise your budget, forecast and scenario data