Top 5 Interim CFO Firms for Strategic Financial Leadership
Best interim CFO firms: costs, models and who fits
A CFO resigns on a Friday. The board meets in three weeks, the lender wants a covenant update, and a permanent search will take months. That gap is what interim CFO firms exist to fill.
Choosing one is harder than it looks. Most firms sound the same on their websites, yet they work in very different ways. Some place a contractor on your payroll. Some send a partner from their own bench. One is a matching network built for private equity. This guide compares five firms on how they work, who they suit and what they cost, using each firm’s own published information and public filings.
How we compared these firms
We looked at four things: the engagement model, the size and stage of company each firm serves, how fast it can start, and how openly it shows pricing.
Oak Business Consultant publishes this guide and lists itself first. Read that as a disclosure, not a verdict. The other four firms are covered from their own websites, press releases and SEC filings, and none of them has reviewed this page. All prices below are public data points, not quotes.
The five firms at a glance
| Firm | How it works | Best for | Worth knowing |
| Oak Business Consultant | Advisory firm with interim and fractional CFOs | Startups and growing businesses | Also offers financial modeling, fundraising support and UAE services |
| FLG Partners | Partner-led CFO and board advisory firm | Venture-backed and mid-size companies, including public ones | Palo Alto firm founded in 2004 |
| Cowen Partners | Executive search firm that also places interim CFOs | Companies that may hire a permanent CFO next | Lists interim services in New York, Chicago, Los Angeles, Seattle and Dallas |
| BluWave | Matching network for private equity | PE-backed portfolio companies | Nashville firm founded in 2016 |
| NOW CFO | Outsourced CFO, controller and accounting teams | Small and mid-size businesses | Salt Lake City firm operating in 20+ states |
Oak Business Consultant
Oak is an advisory firm, not a staffing agency. Its CFO work sits next to financial modeling, fundraising support and business valuation. That mix helps when an interim mandate includes a capital raise or a hard conversation with a lender.
Oak mainly serves startups and growing businesses, and it runs UAE company and tax services alongside its CFO work. As with any firm, ask for references from companies at your size and in your sector before you sign.
FLG Partners
FLG Partners is a Palo Alto firm founded in 2004. Its partners take CFO roles directly, either interim or permanent, and also serve on boards. The firm says it has worked with more than 500 clients, from startups to Fortune 100 companies.
Its partners show up often in public announcements. Cutera and Amyris each named an FLG partner as interim CFO in 2019. Mitek Systems did the same in 2023.
The Mitek filing also gives a rare price point. The company agreed to pay FLG $615 an hour for its interim CFO. At that rate, 80 hours in a month costs $49,200. Senior partner time is not cheap, so scope the hours before you start.
Cowen Partners
Cowen Partners is an executive search firm that also places interim CFOs. The same team that runs a permanent CFO search can supply the stop-gap while it runs. That is its main advantage.
Its marketing says it places the top 1% of talent. That figure is the firm’s own, so ask for placement data. Search firms also earn most of their fees on permanent hires. Ask how the interim is billed and whether any conversion terms apply if you keep the person.
BluWave
BluWave is a matching platform, not a CFO firm. Private equity firms and their portfolio companies use it to find interim executives and specialist consultants from an invite-only network. The company says it serves hundreds of PE firms.
One third-party profile reports shortlists within a day and no matching fee for the company making the request. Confirm who bills you and at what rate before you agree to anything.
Its core customer is a PE sponsor. BluWave says it is expanding to growth-stage and mid-market companies, so founder-led businesses can ask, but expect a sponsor-first process.
NOW CFO
NOW CFO is a Salt Lake City firm that supplies outsourced CFO, controller and accounting teams. Interim or fractional CFO work is one of several options. In June 2025, private equity firm CenterOak Partners completed a majority recapitalization of the company.
The firm says it works in more than 20 states and uses more than 500 full-time professionals in the US and abroad. That depth suits a company that needs its accounting function rebuilt along with a new finance leader. Ask who your day-to-day contact will be, since the model relies on a large team.
Other names on most shortlists
Robert Half, Korn Ferry and PwC come up in most comparisons. One recent comparison from Eightx, which is itself an interim CFO firm, describes Robert Half and Korn Ferry’s interim arm as staffing or hybrid models. It positions PwC for companies above roughly $100 million in revenue. Treat that as one competitor’s view and check each firm directly.
What an interim CFO costs
Interim CFOs cost more than fractional ones because they work close to full time. A fractional CFO might give you 10 to 40 hours a month. An interim covers most of a working week or more.
| Data point | Figure | Context |
| Eightx comparison, interim | $15,000 to $35,000 a month | US firms serving companies up to about $150 million in revenue |
| Eightx comparison, fractional | $5,000 to $15,000 a month | Part-time engagements |
| Mitek Systems SEC filing, 2023 | $615 an hour | FLG Partners partner acting as interim CFO |
The same Eightx comparison says staffing agencies add 25% to 40% on top of the contractor’s pay rate. That claim comes from a competitor, so ask any agency to show its margin.
For part-time pricing, read Oak’s guide to the cost of a fractional CFO.
Interim, fractional or full-time?
The right model depends on what changed in your business.
| Situation | Best fit |
| Your CFO quit, took leave, or a deal or restructuring needs full-time attention | Interim |
| You have no CFO and need planning, cash forecasts and investor reporting | Fractional |
| The workload needs a permanent executive in the building every day | Full-time |
One recent comparison puts interim engagements at 3 to 12 months. Many companies start with an interim and then hire a permanent CFO, or step down to a fractional arrangement once things settle.
Staffing agency or partner-led firm?
Agencies place a contractor on your payroll. The contractor may be excellent, but the agency usually adds a margin and the person has less stake in the result. Partner-led firms send someone from their own bench, so the firm answers for the work.
Neither model is wrong. Agencies suit companies that want a wide pool of candidates. Partner-led firms suit companies that want one accountable team. The costs often land close together, so judge the model rather than the logo.
Six questions to ask every firm
- Who will do the work, and will I meet them before I sign?
- What is the start date, in writing?
- What exactly will I be billed: rate, hours, expenses and any margin?
- What are the notice period and exit terms?
- Can I speak to two clients at my size and in my situation?
- What happens when a permanent CFO arrives, and are there conversion fees?
Frequently Asked Questions
What does an interim CFO do?
An interim CFO takes over the CFO seat for a set period. The job usually covers cash management, reporting, lender and board communication, and keeping the finance team steady until a permanent leader starts.
How much does an interim CFO cost?
One recent comparison puts US interim CFO engagements at $15,000 to $35,000 a month. Individual partners at senior firms can bill by the hour. A public filing from 2023 shows $615 an hour for one FLG partner.
How long does an interim CFO stay?
Most engagements run 3 to 12 months, according to one recent comparison. The length depends on whether you are covering a leave, running a deal or waiting for a permanent hire.
What is the difference between an interim and a fractional CFO?
An interim CFO fills a vacancy at close to full-time intensity for a limited period. A fractional CFO works part time and often stays for years. Interim suits a gap. Fractional suits a company that needs senior input but not a full-time executive.
How fast can an interim CFO start?
It varies by firm. The same comparison lists 2 to 6 weeks for most larger firms and 7 to 14 days for one specialist. Get a start date in writing, because an emergency does not wait for a placement search.
Should I use an agency or a partner-led firm?
Use an agency if you want a broad candidate pool and can wait for the search. Use a partner-led firm if you want one team to own the result. Ask each firm about margin, who does the work and what happens at handover.
Write the brief before you call anyone
The firm matters less than the brief. Before the first call, write a one-page mandate: the three decisions the interim must make in the first 90 days, who they report to, and what “done” looks like. A firm that questions that brief is usually worth more than one that can simply start Monday.
If your business needs experienced finance leadership quickly, Oak’s temporary and interim CFO services can scope an engagement around your mandate. Contact the team to talk through your situation.
