Set a category budget
Change what a category is allowed to spend, and see what that does to the rest of your budget first.
On the Budget screen, press and hold the coin you want to change. A plain tap flips it instead, which is the more common gesture and easy to hit by accident.
Tap the Edit tab, then BUDGET AMOUNT, and enter the new figure.
Tap Save and Carlo shows you the revised split before committing anything: Month Coins, Year Coins divided by twelve, Bills, Goals, and whether the total now lands under or over your income. Tap Save again to commit. That second step only appears when you have actually changed the amount, so an edit to a name or color saves in one go.
Year coins work the same way. Scroll past your month coins to the year heading and press and hold one there. The figure you enter is for the whole year, and Carlo divides it by twelve when it shows your monthly split.
Budgets belong to the current month. Open a past month and the amount is read-only, marked as a historical record, because rewriting an old budget would change what your history meant. A goal coin cannot be edited either, since it holds exactly what the goal saved.