Design cost centres, budgets and rules

Budgets

Amount, period, rollover, soft vs. hard limit.

A budget puts an amount and a period on a cost centre, and keeps a ledger of what has been consumed against it. It is the control the customer's controller actually asked for.

Before you begin. The cost centre has to exist first, and you need three answers from the customer: the amount, the period it covers, and — the one people forget — what should happen when it runs out. A budget that only reports is a different product from a budget that blocks.

What a budget carries

FieldWhat it decides
Cost centreWhat it applies to
AmountThe starting value, in the organization's currency
PeriodStart and end — a financial year, a quarter, a month
RecurrenceWhether a fresh budget opens automatically for the next period
SequenceThe order in which budgets are consumed when a cost centre has several
Remaining valueWhat is left. Maintained by the ledger, never typed

Budgets are monetary only. There is no quantity budget, no "twelve laptops a year". Customers ask for it; the answer is a restriction on the cost centre or a rule on the product, not a budget.

Several budgets on one cost centre

A cost centre can carry more than one budget at a time, and they are consumed in sequence order: the first is drained, then the second, then the third.

This is how the real cases are modelled: a carried-over remainder as sequence 1 with this year's allocation behind it, so the old money is spent first; a one-off supplement — the €15,000 approved in March for an unplanned repair — as its own budget so it can be reported on separately; a project pot alongside the running budget on the same cost centre.

The last budget in the sequence may go negative. That is deliberate. When budgets are configured as soft limits, an order that overruns has to land somewhere, and a visible overrun on the final budget is far better than a silent failure or a blocked order at the worst moment. A negative remaining value is a report, not a bug — it is exactly the number the customer's controller wants to see in January.

Rollover

A recurring budget opens a new period automatically with its configured amount. The decision to make with the customer is what happens to the remainder:

ChoiceEffectFits
ResetThe new period starts at the full amount. The remainder is goneConsumables, where an underspend should not fund a spree in January
Carry overThe remainder opens as an additional budget ahead of the new one in the sequenceProject and investment budgets

Reset is the safer default and matches how most German controlling departments run Sachkosten. Carry-over is what they use for Investitionen. Ask which one this cost centre is; do not assume from the amount.

Soft limit or hard limit

This is not a property of the budget. It is decided by the approval rule that watches it, and there are three useful settings:

BehaviourRule effectWhat the buyer experiences
Report onlyNo rule at allNothing. Spend is booked and visible; the budget never intervenes
Soft limitpendingOrderOver budget, the cart becomes a purchase request and somebody signs for the overrun
NotifysendEmailThe order goes through; the cost-centre owner is told
Hard limitpreventThe submit is refused. No request, no order
Hard limits stop your revenue, not only their spend. A prevent rule on a maintenance cost centre means that at 15:40 on a Friday in November, the person trying to buy a seal for a leaking machine gets a refusal. Most customers who ask for a hard limit want a soft one — an overrun that a manager signs for. Ask what they want to happen to the genuine emergency before you configure prevent.

Reserve the hard limit for the cases where an overrun really is forbidden: grant-funded budgets, project accounts with an external funder, capital expenditure that has to stay inside an approved figure.

How consumption works

Four movements, and every one appends a ledger entry rather than editing a total:

MomentMovement
A purchase request is submittedreserve — the amount is held
The request is fully approved and the order createdconfirm — the hold becomes consumption
The request is rejected, withdrawn or expireswithdraw — the hold is released
An order is placed with no approval neededcommit — consumed in one step

Held money counts as gone for every other check. Two buyers cannot both spend the last €500 while a request sits undecided. Manual corrections — the controller adding €5,000 mid-year — also post an entry, with a reason of manual and the person who made it. Nothing overwrites the number. See Reading the budget ledger.

Set one up

  1. Open the cost centre in the Cost Centers app and add a budget.
  2. Enter the amount in the organization's currency. Check which currency that is if the customer buys across markets — see Currencies and tax.
  3. Set the period. Use the customer's financial year, which is not always the calendar year.
  4. Set recurrence and the rollover choice.
  5. Leave the sequence alone unless the cost centre already has a budget. If it does, decide explicitly which is drained first.
  6. Configure the rule that gives it teeth — or deliberately none, if this budget is for reporting.

What to check

  • The budget shows its full amount as remaining, and one ledger entry recording that it was opened.
  • Submit a test request against the cost centre. Remaining falls immediately. Reject it. Remaining returns to where it was, and the ledger shows both movements.
  • Ask the customer's controller to compare the remaining value against their own figure for the same period in the first month, not the twelfth.

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