Subcategories are more specific divisions inside a category, allowing an extra level of detail. Technically a subcategory is an ordinary category with a parent filled in — it has the same fields, the same budget and the same annotations.
When it is worth creating one
The signal usually comes from the data, not from planning: when you open a category, look at the month's entries and realize you can no longer answer "where did this money go" without reading line by line, it is time to divide.
- Good candidates: "Car" becoming fuel, maintenance and insurance; "Home" becoming rent, building fees and utilities.
- Poor candidates: divisions that would only exist to separate two or three entries a year. For those, a marker solves it without inflating the tree.
Creating and repositioning
- Create it normally and choose the parent. In the category editor, the "parent category" field is what turns a category into a subcategory. There is no separate type to pick.
- Or promote / demote by dragging. Under Menu › Categories › Move, dragging a category into another makes it a subcategory; dragging it out returns it to the first level. Nothing is written until you confirm.
- Move the old entries. Creating the subcategory does not redistribute the past. Use Menu › Entries › Move from Category, filter by the text that characterizes that expense and move the block at once.
Subcategory budgets
In the budgets screen, opening the subcategories of a category that already has a budget makes the app automatically copy the parent's period, start date and end date into each subcategory that is still at zero — the first time you expand them. The amount is still yours to fill in; what the app spares you is repeating the same cycle setup on every child.
The tree accepts more depth, but almost every question a third level would answer is better answered by a marker — which cuts across categories instead of creating more branches to navigate.