Delete a bill permanently
Remove a bill and everything filed under it. This cannot be undone, and archiving is almost always the better choice.
Open Bills, tap the bill, scroll to the bottom, and tap Delete permanently, the red button below Archive Bill. Read the warning, then tap Delete.
What goes is more than the bill: its budget, its category, every upcoming payment, and every transaction filed under that category. Your category history and spending reports will change to match, because those transactions are genuinely gone rather than hidden.
That is why this is really for test bills and mistakes, something you set up and want gone before it ever held a real payment. If there is actual history on it, Archive Bill instead: the bill leaves your list and every record survives.
In a shared space the button is not there at all. Shared bills can only be archived.