Budget Base Zero: Stop Funding Last Year’s Assumptions

Budget base zero is a planning method where every line of marketing spend is justified from scratch each cycle, rather than using last year’s budget as the starting point. Nothing carries over automatically. Every activity has to earn its place.

It sounds simple. In practice, it forces a level of commercial discipline that most marketing teams quietly avoid, because it removes the single most comfortable habit in budgeting: the assumption that what got funded before should get funded again.

Why Most Marketing Budgets Are Built on Inertia

I have sat in enough budget planning meetings to know how most of them actually work. Someone opens last year’s spreadsheet, adjusts the numbers up or down by a few percent depending on the mood in the room, and the budget is essentially set. The conversation is about the margin, not the whole. Nobody asks whether the underlying activities are still worth doing.

This is incremental budgeting, and it is the default because it is fast, it avoids conflict, and it feels safe. The problem is that it compounds poor decisions. A channel that underperformed three years ago gets funded again, because it was funded last year. A sponsorship that nobody can measure keeps renewing, because it has always renewed. A content programme that generates traffic but no pipeline survives another cycle, because the traffic numbers look respectable enough in a slide deck.

The budget does not reflect strategy. It reflects history. And history is not a plan.

This is one of the core operational challenges that comes up repeatedly in marketing operations, where the gap between what a team says it is trying to do and where the money actually goes is often wider than anyone is comfortable admitting.

What Budget Base Zero Actually Means in Practice

The mechanics are straightforward. You start from zero. Every activity, every channel, every team resource, every agency retainer has to be proposed and justified as if it did not already exist. The default is no spend, not last year’s spend. You build up from there based on what you are trying to achieve and what the evidence says is working.

In a proper zero-based process, each spend proposal needs to answer three questions. What is this money for? What outcome does it drive? What happens if we do not fund it? If you cannot answer all three clearly, the item does not belong in the budget. Not yet.

Forrester has written about the discipline required to move marketing planning from reactive to strategic, noting that the shift from panic-mode planning to structured planning requires both process change and a different kind of commercial accountability. Budget base zero is one of the mechanisms that forces that shift. It makes the commercial logic visible, rather than buried in a carry-forward figure nobody questions.

What it is not: an annual cost-cutting exercise dressed up as strategy. That is a misuse of the method, and it produces the wrong result. If you go into a zero-based process with a predetermined cut target, you will end up justifying the cuts rather than genuinely evaluating the spend. The goal is clarity, not reduction for its own sake.

The Hidden Cost of Carrying Forward Bad Spend

When I was running an agency, we did a proper audit of where client retainer budgets were actually going across a handful of accounts. Not what the scope of work said, but where the hours and the media spend were landing in practice. In almost every case, there were activities that had been running on autopilot for 18 months or more that had no clear commercial rationale. They existed because they had always existed, and nobody had stopped to ask whether they should still exist.

The clients were not getting ripped off. The work was being done. But it was the wrong work, and everyone had been too comfortable with the rhythm of the retainer to notice. That is the hidden cost of incremental budgeting: it is not just wasted money, it is misdirected effort at scale.

MarketingProfs has made the point that marketing process without commercial grounding becomes an end in itself, where the activity looks productive but the outcomes are thin. Budget base zero is one way to break that pattern, because it forces the commercial question at the start of the cycle rather than at the post-campaign review when the money has already been spent.

The categories where I see this most often are brand activity with no measurement framework, event sponsorships where attendance is the only metric, content programmes measured on volume rather than pipeline contribution, and legacy agency relationships where the scope has not been revisited in years. None of these are inherently bad investments. But without a justification process, they become permanent fixtures rather than deliberate choices.

How to Run a Zero-Based Budget Process Without It Becoming a Political Fight

This is where most attempts at budget base zero fall apart. The method is sound. The execution is where it gets messy, because zeroing out budgets means zeroing out the assumptions and sometimes the status of the people who built them. If you are not careful, the process becomes defensive rather than analytical.

A few things that help.

First, separate the evaluation from the allocation. Before you start building the new budget, spend time mapping what you currently fund and what each item is supposed to deliver. Do this without a cut target in mind. You are trying to understand the portfolio, not justify a predetermined outcome. Once you have a clear picture of what exists and what it is meant to do, the allocation conversation becomes much more grounded.

Second, use a consistent evaluation framework. Every spend proposal should be assessed against the same criteria: strategic fit, expected return, confidence in the evidence, and what would happen if it were not funded. This removes the subjectivity that makes budget conversations political. You are not arguing about whether someone’s pet project is good or bad. You are applying the same questions to everything.

Third, do it early. The worst version of zero-based budgeting is the one that happens in November when the finance team needs numbers by the end of the month. You end up rushing the justification process, which means you end up with last year’s budget with a zero-based label on it. The process needs time to work properly, which means starting it in late summer or early autumn at the latest.

Forrester’s thinking on designing marketing operations at scale is useful here. The structural point is that budget decisions and planning decisions need to be aligned, not sequential. If you plan your campaigns first and then figure out the budget, you are doing it backwards. Zero-based budgeting works best when the planning and the financial justification happen in parallel, not as separate processes.

What Zero-Based Budgeting Reveals That Incremental Budgeting Hides

One of the most valuable things about running a genuine zero-based process is what it surfaces. Not just where the money is going, but where the measurement gaps are. If you cannot justify a spend item, it is often because you cannot measure it. And if you cannot measure it, you have been funding it on faith.

Early in my career, I taught myself to code because a managing director told me the website budget did not exist. That constraint forced me to understand what the website actually needed to do, rather than what a nice-to-have spec would include. Zero-based budgeting does something similar. It forces you to understand what each activity actually needs to achieve, rather than what it has historically been allowed to do.

The measurement gaps are particularly revealing. When a team cannot articulate what success looks like for a spend item, that is not a measurement problem. That is a strategic problem. The measurement gap is a symptom of unclear objectives, and zero-based budgeting makes that visible in a way that incremental budgeting never does.

Privacy and data changes are also shifting the measurement landscape in ways that make this more urgent. The regulatory environment around data and tracking has already changed what marketers can measure and how. If your budget justifications rely on attribution models that depend on third-party data that is becoming harder to access, your evidence base is weaker than it looks. A zero-based process forces that reckoning rather than letting it slide.

The Difference Between Zero-Based Budgeting and Cutting Budgets

I want to be direct about this because the conflation causes real damage. Zero-based budgeting is not a cost reduction tool. It is a resource allocation tool. The output of a proper zero-based process might be a larger budget than the previous year, if the evidence justifies it. It might be a smaller budget. It might be the same total with a completely different distribution across channels.

The point is that the number is the result of deliberate evaluation, not a carry-forward with adjustments. That is a fundamentally different thing.

When I was growing an agency from around 20 people to over 100, one of the things I learned about operational discipline was that the teams who performed best were not the ones with the biggest budgets. They were the ones who were clearest about what they were trying to do with the money they had. Zero-based thinking, applied to how we structured our own internal investments in people, tools, and capability, was part of what made that growth sustainable rather than chaotic.

The same logic applies to client-side marketing budgets. Clarity about purpose beats scale of spend. A smaller, well-justified budget almost always outperforms a larger budget that has accumulated activities without accountability.

Applying Zero-Based Thinking to Specific Budget Categories

The method applies differently depending on the type of spend. Here is how I think about the main categories.

Paid media. This is the easiest category to apply zero-based thinking to, because the data exists. Every channel, every campaign type, every audience segment should be able to demonstrate contribution to pipeline or revenue. If it cannot, the burden of proof is on the team proposing to continue it. I have seen paid search campaigns generate six figures of revenue within a single day from a well-structured setup, and I have seen equivalent budgets disappear into campaigns that produced traffic but no commercial return. The difference is almost always in the rigour of the brief and the clarity of the conversion objective. Zero-based budgeting forces that rigour at the planning stage.

Agency and technology costs. These are the categories where inertia is most dangerous. Agency retainers in particular tend to expand to fill the scope that was agreed two years ago, regardless of whether that scope still reflects the business’s priorities. Technology contracts renew automatically. A zero-based review of these costs should ask what the tool or relationship is actually delivering today, not what it was delivering when it was first commissioned. Data compliance obligations have also changed what some tools are permitted to do, which makes the review even more important.

Brand and content investment. These are the hardest to justify in a zero-based process because the returns are long-cycle and harder to attribute. That does not mean they should not be funded. It means the justification needs to be more sophisticated than a short-term ROI calculation. The right question is not whether brand investment generates measurable return in the next quarter. The right question is whether the business has a clear theory of how brand investment contributes to commercial outcomes over time, and whether the proposed spend is consistent with that theory.

Events and sponsorships. These are where I most often find spend that would not survive scrutiny. The justification is usually some combination of brand presence, relationship building, and pipeline opportunity. All of those can be legitimate. But they need to be specific, not generic. Which relationships? With whom? What pipeline has historically come from this event? If the answers are vague, the spend is probably being carried forward on habit rather than evidence.

Building the Commercial Case Internally

One of the practical challenges with zero-based budgeting is that it requires marketing leaders to make a commercial case for spend in a way that incremental budgeting does not. When you are defending a carry-forward, the burden of proof is low. When you are building a budget from scratch, you have to articulate why each item deserves to exist.

This is actually a good thing. Marketing teams that can articulate the commercial logic for their spend are more credible with finance and with the board. They get more autonomy because they have demonstrated the discipline to justify it. The teams that struggle to make the case tend to find their budgets cut by finance rather than allocated by strategy, which is a much worse outcome.

The internal communication piece matters too. Getting buy-in from senior stakeholders for a new planning process requires framing it correctly. If you present zero-based budgeting as a cost-cutting exercise, you will get resistance from teams who feel threatened. If you present it as a way to make better use of the budget you have and build a stronger case for the budget you need, the conversation is very different.

The Unbounce research on how marketers are thinking about data and accountability points to a broader shift in how marketing is expected to operate: with more transparency, more evidence, and more commercial discipline. Zero-based budgeting is part of that shift. It is not a new concept, but it is increasingly the right response to an environment where every line of spend is under more scrutiny than it used to be.

If you want to go deeper on the operational frameworks that sit around budget planning, the marketing operations hub covers the broader discipline of how marketing functions are structured, measured, and run with commercial intent.

What a Good Zero-Based Budget Actually Looks Like

A well-executed zero-based budget has a few characteristics that distinguish it from a standard budget with a different label.

Every line has a clear objective, not a category description. “Paid search, £150k” is not a budget line. “Paid search targeting mid-funnel demand for product category X, £150k, expected to contribute Y qualified leads at a cost per lead of Z” is a budget line. The difference is whether the number is connected to an outcome or just to an activity.

The budget reflects a prioritisation decision, not just a list of things the team wants to do. If you have more proposals than budget, the zero-based process should make the prioritisation logic explicit. What gets funded first, and why? What gets cut, and on what basis? These decisions should be documented, not just made in a conversation that nobody writes down.

There is a contingency or test budget built in. Zero-based budgeting should not mean zero appetite for new investment. A portion of the budget should be explicitly allocated to testing channels or approaches that do not yet have a performance track record, with clear criteria for what would justify scaling them.

The measurement framework is agreed before the money is spent. One of the most common failures in marketing budgeting is that the measurement approach is designed after the campaign, which means it is designed to show the campaign in the best possible light rather than to evaluate it honestly. In a zero-based process, the measurement framework is part of the justification. If you cannot define how you will know whether this investment worked, you are not ready to fund it.

Privacy changes are also affecting what is measurable. Tracking limitations across major platforms mean that some historical attribution models are no longer reliable. A zero-based review should account for this explicitly, rather than carrying forward measurement assumptions that no longer hold.

The Honest Reason Most Teams Do Not Do This

Zero-based budgeting is more work than incremental budgeting. That is the honest answer. It requires more time, more documentation, more internal negotiation, and more willingness to have uncomfortable conversations about activities that are not working.

Most marketing teams are already stretched. The planning cycle competes with the execution cycle, and when something has to give, it is usually the planning rigour. The result is budgets that are built on last year’s assumptions, funded for another year, and evaluated against metrics that were chosen because they look good rather than because they reflect commercial reality.

I have been in that position. When you are managing a large team and a complex portfolio of clients, the temptation to take the path of least resistance in planning is real. But the teams that build proper planning discipline, even when it is inconvenient, are the ones that compound their performance over time. The ones that skip it tend to find themselves defending budgets they cannot justify to finance directors who have noticed that the numbers do not quite add up.

The investment in the process pays back. Not always immediately, but consistently. And the first time you run a zero-based review and find a meaningful chunk of spend that has been sitting in activities with no clear commercial rationale, the case for doing it again the following year becomes very easy to make.

About the Author

Keith Lacy is a marketing strategist and former agency CEO with 20+ years of experience across agency leadership, performance marketing, and commercial strategy. He writes The Marketing Juice to cut through the noise and share what works.

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