Operating Budgets: How to Build One — A Detailed Guide

Note: This article describes the Danish bookkeeping and digital reporting rules specifically.

An operating budget is a period-based overview of your business's expected income and operating costs, showing the expected operating result. It's one of the most fundamental management tools a business can have — whether it's just starting out, or has existed for decades. Want to see what a fully built operating budget actually looks like? You can download our free example (currently in Danish), built around a fictional company.

What is an operating budget?

The operating budget shows what you expect the business to earn and spend on operations in a given period — typically a financial year, often broken down by month or quarter. It follows the same logic as an income statement, just forward-looking instead of backward-looking: revenue minus costs gives a result.

In practice, "operating budget" and "profit budget" are largely used as synonyms — if you come across both terms, they usually refer to the same document.

Operating budget, cash flow budget and capital expenditure budget — what's the difference?

The three terms are often mixed up, but cover different things:

• The operating budget shows when an item of income or cost belongs, accounting-wise (accrual) — that is, the expected result of operations.
• The cash flow budget shows when money actually moves in and out of the business's account. An order invoiced in January but only paid in March affects the operating budget in January and the cash flow budget in March.
• The capital expenditure budget (investment budget) covers only purchases and sales of fixed assets like machinery, vehicles or fixtures. It's normally kept separate from the operating budget, even though ongoing depreciation on fixed assets is included as a cost in the operating budget.

A business can easily have a great operating budget and still run into cash flow problems, if customers pay late or large bills fall due all at once. That's why an operating budget should generally always be followed up with a cash flow budget.

How an operating budget is structured

Most operating budgets follow the same basic structure, from revenue down to the final result:

1. Revenue

The expected income for the period. Consider breaking revenue down by product or service type, customer group, or department, so you can later see where a deviation stems from.

2. Cost of goods sold and variable costs

Costs directly tied to delivering the service or producing the goods — typically materials, goods, or subcontractors. These costs normally rise and fall with revenue.

3. Contribution margin and contribution ratio

Revenue minus cost of goods sold and variable costs gives the contribution margin — the amount left to cover the business's fixed costs and generate a profit. The contribution ratio is the contribution margin expressed as a percentage of revenue, and is one of the most important figures to track on an ongoing basis, because a decline here is often noticed too late if you only look at the bottom line.

4. Fixed costs

Costs that generally don't fluctuate with activity levels in the short term: salaries, rent, insurance, marketing and administration. Budget these line by line rather than as one lump sum — it makes a later variance analysis far more useful.

5. EBITDA

Contribution margin minus fixed costs gives EBITDA — the operating result before depreciation and amortization. It shows earnings from operations themselves, without accounting depreciation effects.

6. Depreciation, amortization and operating result (EBIT)

Subtract ongoing depreciation and amortization on the business's fixed assets from EBITDA, and you get the operating result (EBIT) — the actual result of operations, before interest and tax.

7. Interest and result before tax

Finally, interest expenses are subtracted (and any interest income added), leaving you with the result before tax.

What time horizon should the budget cover?

Most operating budgets are made for a full financial year at a time, broken down by month or quarter for ongoing follow-up. Some businesses instead work with a rolling budget, continuously extended 12 months ahead, rather than resetting the budget at each year-end. Choose the model that fits how predictable your business is — a seasonal business typically benefits most from a monthly breakdown.

Budget follow-up and variance analysis

A budget never checked against reality loses most of its value. Budget follow-up is the ongoing comparison of budgeted and actual figures, typically month by month or quarter by quarter. Find a deviation, and the next step is a variance analysis: is the deviation a one-off event — for example a delayed order — or does it reflect a structural development, like rising prices from a supplier that will continue for the rest of the year? Only the structural type should normally trigger an adjustment to the rest of the year's budget.

Set fixed dates for follow-up — for example the 10th of each month — so it becomes a fixed routine rather than something that slips when everyday work gets busy.

New rules: mandatory digital bookkeeping in 2025 and 2026

If your business hasn't already sorted this out, it's worth knowing about recent changes to the Danish Bookkeeping Act, which directly affect how you record and document the figures your operating budget is built on:

• From January 1, 2025, all Danish companies required to keep accounts — typically ApS and A/S — must use a digital bookkeeping system meeting the Danish Business Authority's requirements.
• From January 1, 2026, the requirement extends to personally owned businesses and associations with net revenue above DKK 300,000 in two consecutive financial years — for existing businesses, the financial years 2024 and 2025.
• Paper-based bookkeeping is no longer sufficient for the businesses covered, and vouchers and accounting records must be stored digitally for at least 5 years.

If your business is covered, properly kept digital bookkeeping is also the best foundation for an accurate operating budget and reliable budget follow-up — the finalized, booked figures are exactly what the budget needs to be checked against.

Why is an operating budget relevant when buying or selling a business?

If a business has consistently budgeted and systematically followed up on its figures, that's a concrete sign it's run professionally and predictably. That's exactly the kind of documentation a buyer typically looks for during due diligence — not just the historical accounts, but also proof that management actively steers and anticipates the business's development.

If a purchase is to be financed wholly or partly with a bank loan, the bank will also often place decisive weight on having a realistic budget building on the business's historical accounts — something we go deep into in our article on the business plan's role in buying and selling a business. A solid operating budget, in other words, isn't just an internal management tool — it can also be part of what makes a deal easier to complete.

Frequently asked questions

Is an operating budget legally required?

No. There's no general legal requirement to prepare an operating budget. It is, however, recognized good business practice, and in practice a prerequisite if you're seeking outside financing.

How often should I update the operating budget?

Most businesses make a new operating budget once a year, but adjust it on an ongoing basis throughout the year when budget follow-up shows significant deviations from the original assumptions.

Are operating budget and profit budget the same thing?

In practice, yes. The two terms are largely used as synonyms in Danish businesses.

Should I make an operating budget if I'm considering selling my business?

It's not a requirement, but an up-to-date, well-documented operating budget can strengthen a buyer's confidence and speed up the due diligence process. See also how it connects to the business plan's role in buying and selling a business.

Want to see what a full operating budget actually looks like? Download our free, fictional example as PDF or Word (currently in Danish), or book a no-obligation call if you'd like sparring on your own budget.