What it means
Most budgeting is incremental: take last year, add 3% for inflation, adjust for anything obviously new. Zero-based budgeting refuses that starting point and asks each budget holder to rebuild the number from the activities they actually plan to run.
The appeal is that it surfaces spending nobody would approve today. Subscriptions for departed staff, agency retainers that outlived their project and legacy contracts all survive incremental budgeting, because nobody ever looks at the base, only at the increment.
In practice a zero-based cycle runs on decision packages. Each package describes an activity, what it delivers, what it costs and what would happen if it were not funded, and the leadership team then ranks packages against each other until the available money runs out.
The cost of the method is time and goodwill. Rebuilding every line from zero every year is exhausting, so many organisations run zero-based reviews on a rolling basis covering a third of the cost base each year, or reserve the method for discretionary categories such as marketing, travel and professional fees.
It also has a failure mode worth naming. Because it is easiest to justify things with visible short-term output, zero-based budgeting can quietly starve maintenance, training and brand building, which is why sensible schemes ring-fence a minimum for long-horizon spending before the ranking starts.
In practice
Real-world examples
Example 1
A hospital group applies zero-based budgeting to its non-clinical spend and finds $340,000 of annual software subscriptions spread across 62 tools, 19 of which have fewer than five active users. Consolidating those 19 tools removes $96,000 a year without touching patient services.
Example 2
A consumer goods company rebuilds its trade promotion budget from zero after realising a $4,000,000 line had simply been rolled forward for years. Pricing each promotion individually shows that the bottom third of the activity generates $600,000 of incremental sales for $900,000 of spend, and it is cut.
Example 3
A 30-person charity runs zero-based budgeting only on its discretionary categories: travel, events, printing and consultancy. Rebuilding those four lines from scratch takes two weeks and removes $58,000 from a $310,000 total, while salaries and rent are budgeted incrementally to save effort.
Think of it
Imagine packing for a holiday by emptying your entire wardrobe onto the floor first, rather than just grabbing last year's suitcase. You only pack items you genuinely need for this specific trip, leaving old, worn-out clothes behind.
Formula
Calculation
Zero-based budget = Sum of the costs of each individually justified activity
The incremental alternative is: Incremental budget = Prior year spend x (1 + uplift %)
A marketing department spent $1,200,000 last year. Under incremental budgeting with a 5% uplift, next year's budget would be $1,200,000 x 1.05 = $1,260,000 with no further scrutiny.
Under zero-based budgeting the head of marketing prices each activity instead. Paid media comes to $520,000, content production $240,000, events and trade shows $180,000, agency retainers $150,000, and software and tools $85,000.
Adding those gives $520,000 + $240,000 + $180,000 + $150,000 + $85,000 = $1,175,000.
The zero-based figure is $1,260,000 - $1,175,000 = $85,000 below the incremental budget, about 6.7% lower, and $25,000 below last year's actual spend. That $85,000 came almost entirely from two cancelled agency retainers and a set of duplicated software subscriptions.Case study
Seen in the real world
Belmore Freight Systems is a fictional haulage company used here as an illustrative example of zero-based budgeting applied carefully. Its overhead had grown from $6,400,000 to $8,900,000 over four years while revenue grew only 9%, and each annual budget had added an inflation uplift to the previous one without anyone examining the base.
The finance director ran a zero-based review across the four largest overhead categories, which together accounted for $5,200,000. Every budget holder submitted decision packages, and the leadership team ranked 74 packages by contribution rather than by department. Funding stopped at package 61, leaving $4,600,000 approved and $600,000 unfunded.
The unfunded packages included a regional office with three staff who could work from the main depot and a fleet telematics contract that duplicated a system already installed. In this illustrative case Belmore also learned a hard lesson: driver training had been ranked low and cut, and after two costly incidents the following year the company reinstated it and ring-fenced training from future rankings.
Watch out
Common mistakes
- Believing zero-based budgeting is simply a cost-cutting exercise, when its purpose is to move money to the highest-value activities, which sometimes means spending more.
- Applying it to every line including fixed rent, statutory audit fees and contracted salaries, which burns weeks of effort on costs that cannot change this year.
- Running it once, celebrating the savings and reverting to incremental budgeting the next year, which lets the same spending creep back within two cycles.
Questions
People also ask
Does zero-based budgeting take longer than incremental budgeting?
Yes, typically several times longer in the first cycle, which is why many companies run it on a rolling subset of the cost base.
Can it be used in a small business?
Yes, and it is often easier there, because one person can review every activity in a couple of days.
What is a decision package?
A short written case for a single activity setting out what it costs, what it delivers and the consequence of not funding it, used to rank spending against everything else.