Because the overspend shows up in the management accounts weeks after the money went. The budget holder hears about their own budget from somebody else.
A cost centre is a dimension carried on postings — a team, a branch, a project — so income and spend report against whoever owns them.
Every posting carries a cost centre: claims, bills, payroll, journals. Budgets sit on the same dimension, so variance is live and the holder watches it move rather than reading it at close.
An office cost serves three teams. The posting splits by a fixed ratio across three cost centres, so each carries its share and no single team looks artificially expensive.
It will not stop the spend. It commits against budget at order and warns on breach; blocking is available, but that is a policy choice rather than a default.
Purchase orders commit against them, claims and bills post to them, payroll allocates to them, and the P&L filters by them.
Yes, split by ratio or by amount.
Yes, permissions scope by cost centre.
Yes, into a hierarchy, so a division sees its teams consolidated.
Fourteen days, every module, no card. Or half an hour with someone who will run it on your own records and tell you where it does not help.