What it means
Traditional budgeting starts with last year's numbers and adds or subtracts a percentage. That approach is quick, but it quietly locks in old spending, including activities that no longer matter.
Zero-based budgeting starts with a blank page and asks each team to build its budget from zero. In practice, managers break their department into activities, such as running payroll or handling customer queries.
For each one, they state what it achieves, how much it costs, and what would happen if it were reduced or stopped. Senior leaders then rank these activities by value and fund them in order until the money runs out.
The method makes the link between cost and outcome visible, which helps in cost-reduction programmes, turnarounds and post-acquisition integration. It can reveal duplicated work or services that are still being paid for out of habit.
Many organisations find that the discussion itself, not just the numbers, changes how managers think about spending. The nuance is the effort involved.
Building every budget from nothing takes a lot of management time, and it can create short-term thinking if teams cut long-term investments to protect visible costs. Many firms therefore apply it to certain areas in rotation, or only to overhead costs, rather than to the whole company every year.
A good practice is to treat ZBB as a reset that is followed by lighter annual reviews. After a full zero-based exercise, the organisation can roll the approved activity costs forward with sensible adjustments for a few years.
It then repeats the exercise when the business changes significantly.
In practice
Real-world examples.
Example
A consumer goods company applies ZBB to its marketing budget. Every campaign has to be justified by expected sales, and campaigns that cannot show a return are dropped. The freed-up money is moved into the products that sell best.
Example
A hospital group uses ZBB for administrative costs. Each department lists its tasks, the staff hours needed and the alternatives, such as outsourcing. Leaders find that two departments were producing near-identical weekly reports and merge them.
Example
A private equity owner introduces ZBB at a newly acquired manufacturer. The new management team rebuilds the overhead budget line by line over three months. The company reduces overheads by $2,000,000 while protecting the sales and engineering teams.
Formula
Calculation
Zero-based budget = Sum of the costs of all approved activities
A finance department proposes three activities for the coming year: the monthly close at $120,000, supplier payments at $75,000 and management reporting at $45,000. Total = 120,000 + 75,000 + 45,000 = $240,000. Last year's budget, carried forward from the previous period, was $300,000. The saving is 300,000 - 240,000 = $60,000, which is 60,000 / 300,000 = 20%.Case study
Seen in the real world.
Kestrel Foods is an illustrative, fictional packaged-food company with $400,000,000 in annual sales. Overheads have crept up every year as each department added 3% to the prior year budget. The new chief financial officer decides to run a zero-based review of the $60,000,000 overhead budget.
Each department lists its activities and ranks them. The review finds $4,500,000 of spending on reports that nobody reads, subscriptions that overlap and travel that could be replaced by video calls. After debate, the executive team funds the activities that support growth and cuts the rest.
In the illustrative outcome, overheads fall by 7.5%, the equivalent of $4,500,000 out of $60,000,000. The lesson is that starting from zero forces the question of why a cost exists, which a percentage uplift never asks. Kestrel also learns that the process has a cost of its own. Managers spend several weeks preparing activity descriptions, and the finance team runs workshops to challenge the rankings. The chief financial officer decides to repeat the full exercise every three years, with a lighter review in the years between, so the effort stays proportionate to the benefit.
Watch out
Common mistakes.
- Believing ZBB always means cutting costs, when its real purpose is to align spending with priorities, and some activities may receive more funding.
- Applying it to every cost line every year, when the workload can overwhelm managers and produce rushed, poor-quality budgets.
- Cutting long-term investments such as training or maintenance to hit a savings target, when the cost shows up later as lost capability.
Questions
People also ask.
How is ZBB different from incremental budgeting?
Incremental budgeting adjusts last year's figures by a percentage, while ZBB requires every cost to be justified from zero.
How often should a company use ZBB?
Many do a full exercise every few years and use lighter reviews in between, though the right rhythm depends on how fast the business changes.
Does ZBB work for small businesses?
Yes, and it is often easier there, because the owner can review each cost directly without a long approval chain.
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