Interim CFO vs. Fractional CFO: Differences and Costs

An interim CFO runs your finance function full-time for a limited period, usually six to twelve months, for example when the CFO seat is suddenly empty or a crisis needs daily attention. A fractional CFO works with you on an ongoing basis for a few days a month and builds planning, reporting and funding readiness. If you need a finance leader every day for a set period, hire an interim CFO; if you need senior finance leadership regularly but not daily, a fractional CFO is the better fit.

This guide covers the differences in detail, how both models are priced, a worked example comparing three options over twelve months, and six questions that help you decide.

What is an interim CFO?

An interim CFO is a temporary finance leader. They work full-time for one company and take full responsibility for accounting, planning, cash and funding. Every assignment has a clear trigger, and it ends when that trigger is resolved or a permanent hire starts.

To act with real authority, an interim CFO is often appointed managing director or given a registered power of attorney. In a German GmbH that power is called Prokura, and under section 49 of the German Commercial Code (HGB) it covers almost every transaction the business involves. An appointment as managing director comes with the duties of that office, including liability under section 43 of the GmbH Act and, in a crisis, the duty to file for insolvency under section 15a of the Insolvency Code (InsO).

Typical triggers for an interim CFO:

• Vacancy: your CFO leaves and the successor is not in place yet, while closings, reports and bank meetings carry on.
• Crisis: cash is running short, and someone has to manage payments every day and talk to banks and shareholders.
• Large transaction: a sale or an acquisition creates months of extra work that the team cannot carry next to daily business.
• Rebuild: after an acquisition or a carve-out from a group, a stand-alone finance function has to be set up.

What is a fractional CFO?

A fractional CFO is an experienced finance leader who works part-time for several companies at once. Fractional simply means a share: you get the experience of a CFO in the amount you need, usually on a few fixed days each month.

In Germany the basis is usually a service contract under section 611 of the Civil Code (BGB), either with the person or with an advisory firm. A fractional CFO is rarely appointed managing director and acts with narrowly defined powers, for example for specific bank meetings. Responsibility for the books stays with the managing directors, as section 41 of the GmbH Act requires.

The model suits companies whose finances have outgrown what the tax adviser delivers but that cannot yet justify a full-time CFO. Common triggers are a planned funding round, a bank loan, investors who expect monthly reports, or a sale one or two years away.

Outsourced CFO, part-time CFO, CFO as a service: what do the terms mean?

The labels are used loosely. Here is how to read them:

• Outsourced or external CFO: the umbrella term for any finance leader who is not on your payroll. In practice it usually means a fractional CFO.
• Part-time CFO: another name for a fractional CFO.
• CFO as a service: usually a package of a part-time CFO plus bookkeeping or controlling delivered by a team. Accounting firms and bookkeeping providers sell under this name as well.
• Interim manager: the umbrella term for temporary leadership in any function. The interim CFO is the finance version.

Do not buy the label. Three questions clarify any offer: how many days a month will the person work for you, for how long, and with which powers?

What does an interim or fractional CFO actually do?

The tasks overlap, but the weighting differs. An interim CFO is deep in daily operations and often leads a team. A fractional CFO builds structures that your own team can run afterwards.

• Cash: a rolling liquidity plan that shows how long the money lasts, weekly in a crisis and monthly otherwise.
• Planning and budget: a financial model that links profit and loss, balance sheet and cash, plus the annual budget.
• Reporting: a monthly pack with key metrics and budget versus actuals for management, shareholders and the advisory board.
• Banks and investors: preparing bank meetings, tracking loan covenants and keeping investors informed.
• Transactions: preparing a funding round or a sale, building the finance section of the data room and answering due diligence questions.
• Finance function: a reliable monthly close agreed with the tax adviser, clear approval rules and the right software.

When do you need an interim CFO and when a fractional CFO?

Two things decide: how much of each day the work takes, and how long the need lasts.

An interim CFO fits these situations:

• Your CFO resigns in the middle of a sale or a funding round.
• Cash is tight, and someone has to steer payments every single day.
• A finance team of several people has nobody leading it.
• Two finance departments have to merge after an acquisition.

A fractional CFO fits these situations:

• The managing director has run finance on the side, and that no longer works.
• A funding round is six to twelve months away.
• Investors or banks ask for reliable monthly figures.
• You want to prepare a sale in one to two years.

Lead time matters before a round. Investors read the quality of your monthly numbers as a sign of how well you run the company. How to approach the right investors afterwards is covered in our guide on how to find investors. The same logic applies before a sale, see our guide on exit strategy for founders.

How much does an interim CFO cost compared with a fractional CFO?

Both models are usually priced in days, just in very different quantities.

• Interim CFO: usually a day rate for the days actually worked. Full-time adds up to roughly 18 to 20 days a month. If an agency places the person, its share is normally built into the day rate.
• Fractional CFO: either a fixed monthly fee for an agreed number of days or a day rate. Extra days are agreed for busy phases such as due diligence.
• Permanent CFO: salary, employer social security contributions, often a bonus and equity. On top come recruiting fees and the months until the person can start.

Reliable market data on day rates is hard to find, and quoted figures depend on experience, industry, situation and responsibility. Ask two or three providers for an offer and compare exactly which services and how many days each price includes.

Worked example: three options over twelve months

A software company with 30 employees plans to start a funding round in nine months. So far the managing director runs finance and the tax adviser does the books. The comparison covers twelve months. All figures are assumptions for the calculation, not market prices.

• Day rate for both external models: 1,500 euro
• Interim CFO, full-time: 18 days a month
• Fractional CFO: 4 days a month, 8 days in the three months of due diligence
• Permanent hire: total cost to the company of 168,000 euro a year, recruiting fee of 42,000 euro, start after a four-month search

1. Interim CFO: 18 × 1,500 = 27,000 euro a month, or 324,000 euro over twelve months.
2. Fractional CFO: 4 × 1,500 = 6,000 euro a month, or 72,000 euro over twelve months. Add four extra days in each of three months: 3 × 4 × 1,500 = 18,000 euro. The total is 90,000 euro.
3. Permanent hire: 168,000 ÷ 12 = 14,000 euro a month. The person works eight of the twelve months: 8 × 14,000 = 112,000 euro. With the recruiting fee of 42,000 euro the total is 154,000 euro.

In this case the fractional CFO is the clear choice. They start in month one, build planning and reporting well before the round and cost less than a third of the interim option. A full-time interim CFO would be oversized because there is no full-time workload yet. The permanent hire arrives four months later and commits you for the long term.

The example also gives you a simple threshold. Divide the monthly cost of a permanent CFO by the day rate: 14,000 ÷ 1,500 is about 9.3 days. If you need more than roughly nine days of CFO work every month on a lasting basis, your own hire becomes cheaper on paper, even before you count recruiting and onboarding.

CFO, controller or tax adviser: who does what?

Many founders wonder whether they need a CFO at all or whether a controller or the tax adviser is enough. The roles complement each other; they do not replace each other.

• Full-time CFO: leads finance every day, manages the team and often sits on the management board, as described in our glossary entry on the chief financial officer. Brings continuity, but costs the most and takes months to hire.
• Interim CFO: the same role for a limited time and without a lasting commitment. Solves an acute problem, then hands over.
• Fractional CFO: sets the frame for planning, control and funding on a part-time basis. Often the step before your own finance lead.
• Controller: analyses the numbers in daily operations, such as costs and variances from plan, and is usually an employee. Controlling provides the basis; the CFO decides what the numbers mean for strategy and funding.
• Tax adviser or accountant: handles bookkeeping, annual accounts and tax returns and mostly looks backwards. In Germany, professional help in tax matters is reserved for licensed professions under section 2 of the Tax Advisers Act (StBerG). A CFO without that licence does not give tax advice and works alongside your tax adviser instead.

A good split of work looks like this: the tax adviser keeps the books and prepares the accounts, a controller or bookkeeper prepares the figures, and the CFO turns them into planning, control and investor reporting.

Which model fits you? Six questions

1. How many days a month of real CFO work are there? Estimate honestly what the monthly close, reporting, planning and investor calls take. If the need sits below the threshold from the example, that points to a part-time model.
2. Is the need temporary or permanent? A six-month gap calls for a different answer than a task that stays.
3. Does the person have to act fully on behalf of the company? If banks in a crisis expect someone with authority to sign, you need a managing director or Prokura. That points to an interim CFO.
4. Is there a team that needs daily leadership? Several people in accounting and controlling need someone every day. A few days a month will not do.
5. How far away is the next transaction? Six to twelve months before a round is a good time to bring in a fractional CFO. If due diligence starts next month and nobody knows the numbers, you often need full-time support.
6. Who takes over afterwards? Plan the handover from day one. A good temporary CFO leaves behind a model and processes that your team can run on its own.

When you do not need a CFO at all

Not every company needs a CFO. If your tax adviser delivers clean monthly figures on time, no round or loan is planned and the business is easy to oversee, a simple cash plan that you maintain yourself is often enough. A strong controller on the team can also cover the gap for a while. A CFO starts to pay off once decisions on hiring, capital and growth are being made without reliable numbers.

Common mistakes

• Choosing the wrong model. If you cover a full-time need with four days a month, nobody is there exactly when investors or buyers expect answers.
• Starting too late. A few weeks before a round you cannot build a financial model, monthly figures and a data room to the quality investors expect.
• Trusting the label. Behind "CFO as a service" there is sometimes mostly bookkeeping. Check who exactly will work for you and on how many days.
• Leaving powers unclear. Without written rules on bank access, powers of attorney and approvals, uncertainty follows. Larger payments should always need two people to approve them.
• Trying to hand off responsibility. The managing directors stay responsible for the books and for liquidity, even when an external CFO does the work.
• Ignoring employment status. If an individual works under instruction and is embedded like an employee, German social security law may treat the role as employment. A status determination procedure under section 7a of Book IV of the Social Code (SGB IV) brings clarity.
• No handover plan. If the assignment ends without documentation, the next finance lead starts from scratch.

Frequently asked questions

What is the difference between an interim CFO and a fractional CFO?

An interim CFO works full-time for one company for a limited period, while a fractional CFO works part-time on a few days a month on an ongoing basis. The interim CFO solves an acute problem such as a vacancy or a crisis. The fractional CFO builds planning, reporting and funding readiness and stays with you for longer.

How much does an interim CFO cost?

It depends on the day rate and the number of days worked. Full-time adds up to roughly 18 to 20 days a month, so the monthly cost is usually well above the monthly salary of an employed CFO. In return you avoid recruiting fees, long notice periods and equity promises.

How many days a month does a fractional CFO work?

Usually a few fixed days a month, depending on the size and stage of the company. Before a funding round or during due diligence the scope goes up for a while. You agree the number of days in the contract.

Is an outsourced CFO the same as a fractional CFO?

Mostly, yes. Outsourced or external CFO is the umbrella term for any finance leader who is not employed, and in everyday use it almost always means the part-time model. If in doubt, ask for the scope in days per month.

Does a fractional CFO replace my tax adviser or accountant?

No. Bookkeeping, annual accounts and tax returns stay with your tax adviser. The CFO builds on their figures and turns them into planning, control and reporting.

When should you hire a full-time CFO?

When finance decisions come up every day, a finance team needs leading or several entities have to be managed. On paper the hire pays off once you need more days each month than an external CFO delivers for the cost of one monthly salary. A fractional CFO often prepares that transition.

Can an interim CFO be appointed managing director?

Yes, that is common. With the appointment the person takes on the duties of a managing director, including liability under section 43 of the GmbH Act. Often Prokura or clearly defined powers are enough.

How Roemer Capital helps

Roemer Capital is an independent fundraising and M&A advisory boutique based in Düsseldorf. We work with technology companies that have a product in the market and running revenue on funding rounds from 1 million euro, on company sales and as a fractional CFO. In that role we take on liquidity planning, the financial model, investor reporting and the preparation of the next round. You pay a fixed monthly fee based on the days agreed per month. Bookkeeping, annual accounts and tax stay with your tax adviser.

If you need a full-time finance leader for a limited period, for example to fill a vacancy or to handle an acute crisis, an interim CFO is the right model. We will tell you openly which option fits your situation in a free intro call.

Note

As of October 2026. This article is not legal or tax advice.