Author: Taylor Warfield, Former Bain Manager and interviewer

Last Updated: May 2, 2026

 

Why companies hire consultants is one of the most common questions people ask when they first learn about consulting. The short answer is that companies hire consultants to solve important problems faster, cheaper, and better than they could on their own. The global management consulting market is worth over $490 billion, according to Fortune Business Insights, and it is growing at roughly 5.6% per year.

 

In this article, I will walk you through the 10 real reasons companies spend millions on consultants every year. Understanding these reasons will not only give you a clearer picture of what consulting actually is, but also help you perform better in consulting case interviews and fit interviews.

 

But first, a quick heads up:

 

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Why Do Companies Hire Consultants?

 

Companies hire consultants because they need results they cannot produce internally. Sometimes the gap is expertise. Sometimes it is bandwidth. Sometimes it is objectivity. In my experience at Bain, every client engagement boiled down to one or more of these 10 reasons.

 

According to IBISWorld, the U.S. management consulting industry alone is worth $411.7 billion in 2026, with over 1 million consulting businesses operating nationwide. That number reflects just how widespread the demand for outside help really is. Below, I will break down each reason in detail.

 

What Are the Top 10 Reasons Companies Hire Consultants?

 

1. To Access Specialized Expertise They Do Not Have In-House

 

The most common reason companies hire consultants is to tap into specialized knowledge that does not exist within their organization. According to industry estimates, roughly 1.5 million people work in the consulting sector globally, and many of them possess highly specialized skills in areas like supply chain optimization, digital transformation, M&A due diligence, and organizational design.

 

Hiring a full-time expert in each of these areas would be prohibitively expensive. A company might need a Lean Six Sigma specialist for a three-month project but have zero use for that skill set the rest of the year. Consultants solve this problem by providing on-demand expertise exactly when it is needed.

 

At Bain, I worked on projects spanning private equity due diligence, pricing strategy, and post-merger integration. No single company would need all three skill sets at once, but each client needed one of them urgently. That is the power of a consulting firm. It aggregates specialized talent and deploys it to the clients who need it most. If you want to learn more about the specific types of consulting that exist, I have a detailed breakdown.

 

2. To Get an Objective, Outside Perspective

 

Companies are often too close to their own problems to see them clearly. Internal teams develop blind spots. They fall victim to groupthink, where everyone shares the same assumptions because they have been operating in the same environment for years. According to research from MIT Sloan, outsiders are more likely to connect disparate ideas because they have fewer preconceptions than insiders.

 

Consultants provide a fresh set of eyes. Having worked across dozens of companies and industries, they can spot inefficiencies and opportunities that internal employees would never notice. In my Bain projects, some of the highest-impact recommendations came from observations that seemed obvious to us as outsiders but had been invisible to the client for years.

 

3. To Supplement Their Staff on High-Priority Projects

 

Sometimes a company has a critical project but simply does not have enough people to work on it. Day-to-day operations still need to run, and pulling employees off their regular jobs creates problems elsewhere. According to data shared on Glassdoor, the average hiring process takes 23.7 days just to make a decision, and that does not include onboarding or training.

 

Consultants solve this staffing gap immediately. A consulting firm can deploy a team of four to six people within days, all of whom are trained to get up to speed quickly. Whether it is a cost reduction program that needs a dedicated team for six months or a post-merger integration requiring 50 people for a month, consultants fill the gap without the overhead of permanent hires.

 

4. To Provide Political Cover for Tough Decisions

 

This is the reason nobody talks about openly, but it is one of the most common reasons companies hire consultants. Some decisions are politically difficult to make internally. Layoffs, salary restructurings, closing a division, and killing a pet project of a senior executive all fall into this category.

 

Hiring an outside firm gives leadership the ability to point to independent analysis when making unpopular moves. If a CEO needs to cut 20% of the workforce, it is much easier to say an external team conducted the analysis and recommended the restructuring. This is not cynical. It is practical. The right decision is the right decision regardless of who identifies it, and sometimes having a third party validate that decision is what makes execution possible.

 

5. To Transfer Best Practices Across Industries

 

Consultants have a rare advantage that almost no internal employee can replicate. They work with multiple companies in the same sector and across different industries facing similar problems. A consultant who helped a beverage company optimize its supply chain last quarter can apply those same lessons to a pharmaceutical company this quarter.

 

This cross-pollination of ideas is one of the highest-value things consultants provide. According to Fortune Business Insights, the strategy consulting segment alone is valued at over $78 billion globally, and much of that spending is driven by companies wanting access to the insights consultants have gathered from their work with competitors and adjacent industries.

 

6. To Drive Change and Overcome Internal Resistance

 

People do not like change. This is true in personal life and even more true inside large organizations. Before implementing change, management has to navigate employee morale, corporate culture, legacy processes, and internal politics. These forces create enormous resistance to even the most obviously beneficial changes.

 

Consultants are effective change agents because they are outsiders. They do not suffer from status quo bias, which is the tendency to want things to remain the same simply because that is how they have always been. In my experience at Bain, some of our most impactful projects involved helping clients implement changes that their internal teams had known were necessary for years but could never push through.

 

7. To Train and Develop Their Employees

 

Companies increasingly use consultants to upskill their own teams. When a company adopts new technology, enters a new market, or restructures its operations, employees need new skills. Sending large groups to external training programs is expensive and disruptive. Bringing in a consultant to train employees on-site using real company data and scenarios is far more effective.

 

A landmark World Bank and Stanford study found that companies that followed management consultants' recommendations improved their productivity by 10%. The study also showed improvements in product quality and inventory management. These results held across multiple countries, demonstrating that the benefits of consulting are not limited to a specific region or industry.

 

8. To Validate Strategy and Secure Stakeholder Buy-In

 

Many companies already have a good idea of what they should do. But having an idea and getting the board, investors, or other stakeholders to approve it are two very different things. Consultants provide independent validation that a strategy is sound.

 

This is especially common in fundraising situations. A bank or investor might require third-party validation of a business plan before providing capital. It is also common in board-level decisions where the CEO needs external backing to move forward with a controversial strategy. The consultant's role here is less about discovering something new and more about confirming that the company's leadership is on the right track.

 

9. To Execute Time-Sensitive Projects at Speed

 

Speed is often the deciding factor. When a company faces a time-sensitive opportunity or crisis, it cannot wait months to hire, onboard, and train a team. Consulting firms maintain pre-built teams with common methodologies and shared work styles. They can be deployed in days and start producing results immediately.

 

This speed advantage is hard to overstate. At Bain, I was staffed on projects where the client needed answers within weeks, not months. The company could not have assembled an internal team that quickly, and even if they could, that team would have needed months to develop the analytical frameworks, data collection processes, and presentation formats that our team already had ready to go.

 

10. To Convert Fixed Labor Costs into Variable Costs

 

There is a straightforward economic argument for hiring consultants. Full-time employees come with salaries, benefits, office space, equipment, and long-term commitments. Consultants convert all of that into a variable cost. You pay for a specific project over a defined period, and when the project ends, the cost stops.

 

This flexibility is particularly valuable during uncertain economic conditions. According to IBISWorld, demand for consulting services grew steadily even as companies cut their permanent headcount during recent economic downturns. Companies used consultants to maintain strategic momentum without taking on the risk of permanent hires they might need to lay off later.

 

How Much Do Companies Spend on Consultants?

 

Companies collectively spend hundreds of billions of dollars on consulting every year. The table below breaks down the global consulting market by segment.

 

Consulting Segment	Estimated Global Market Share	Example Projects
Operations Consulting	~30% of total market	Supply chain redesign, process optimization, cost reduction
Technology / IT Consulting	~20% of total market	Cloud migration, ERP implementation, cybersecurity strategy
Financial Advisory	~20% of total market	M&A due diligence, restructuring, valuation
Strategy Consulting	~15% of total market	Market entry, corporate strategy, competitive positioning
HR Consulting	~15% of total market	Organizational design, talent strategy, compensation benchmarking

 

According to Mordor Intelligence, the global consulting services market is expected to reach $388.7 billion in 2026 and grow to $490.7 billion by 2031. In the United States alone, the management consulting industry is worth $411.7 billion, according to IBISWorld. Strategy consulting, which is the segment that firms like McKinsey, BCG, and Bain primarily operate in, is valued at over $78 billion globally, based on data from Fortune Business Insights.

 

A single consulting engagement can range from $50,000 for a small project at a boutique firm to $5 million or more for a multi-month project at an MBB firm. Partner-level billing rates at top strategy firms typically exceed $1,000 per hour. To learn about the different firms and how they compare, check out my guides on the consulting career path and tier 2 consulting firms.

 

What Types of Consulting Do Companies Use Most?

 

Companies use six main types of consulting, each focused on a different set of business challenges. The table below summarizes what each type does and who the major firms are.

 

Consulting Type	What They Do	Top Firms
Strategy / Management	Advise on high-level business strategy, market entry, and competitive positioning	McKinsey, BCG, Bain
Operations	Improve supply chains, manufacturing, and day-to-day business processes	Deloitte, Accenture, Kearney
IT / Technology	Lead digital transformation, system implementations, and cybersecurity	Accenture, IBM, Capgemini
Financial Advisory	Support M&A transactions, valuations, restructuring, and forensic analysis	Deloitte, PwC, EY, KPMG
Human Resources	Design org structures, talent strategies, and compensation programs	Mercer, Korn Ferry, Willis Towers Watson
Implementation	Execute strategies developed by management or strategy consultants	Accenture, Deloitte, Capgemini

 

Strategy consulting is the most prestigious and competitive segment, but it represents only about 15% of the total consulting market by revenue. Operations consulting is the largest segment at roughly 30%. For a deeper dive into each type, read my guide on the different types of consulting.

 

Why Does Understanding This Matter for Your Consulting Career?

 

If you are preparing for consulting interviews, understanding why companies hire consultants is not just interesting background knowledge. It directly shapes how you should approach your interviews.

 

In case interviews, you are simulating what a consultant does on a real engagement. The better you understand the client's motivation for hiring a consulting firm, the more relevant and insightful your analysis will be. For example, if the case involves a company considering a market entry, knowing that the client likely hired consultants because they lack internal expertise in that market helps you frame your analysis around the right questions.

 

In fit or behavioral interviews, firms directly ask questions like "Why consulting?" and "What do you think consultants do?" Candidates who can articulate the real value consultants provide, rather than vague statements about "solving problems," immediately stand out. Having coached hundreds of candidates, I can tell you that the ones who understand the business of consulting consistently outperform those who only studied case frameworks.

 

To build out the skills for management consulting and understand what consultants actually do day to day, check out those guides. And if you are just getting started, my complete guide on how to get into consulting covers every step of the process from networking to offer.

 

Frequently Asked Questions

 

What Is the Most Common Reason Companies Hire Consultants?

 

The most common reason is to access specialized expertise that does not exist in-house. Companies face problems in areas like digital transformation, M&A, and organizational restructuring that require deep knowledge their current employees do not have. Hiring a consultant provides that expertise on demand without the cost and commitment of a full-time hire.

 

How Much Does It Cost to Hire a Consulting Firm?

 

Costs vary widely based on the firm and project scope. A small engagement with a boutique firm might cost $50,000 to $200,000. A multi-month strategy project with McKinsey, BCG, or Bain can range from $1 million to $5 million or more. Partner-level billing rates at top firms typically exceed $1,000 per hour, while junior consultants bill at $200 to $500 per hour.

 

Do Consultants Actually Help Companies?

 

Yes. A widely cited World Bank and Stanford study found that companies that implemented management consultants' recommendations improved their productivity by 10%. The study also showed improvements in product quality and inventory management. These results were consistent across multiple countries and industries.

 

Why Don't Companies Just Hire Full-Time Employees Instead of Consultants?

 

There are three main reasons. First, many consulting projects require specialized skills that the company would not need on an ongoing basis. Second, hiring takes time. The average hiring process takes over 23 days, and onboarding adds weeks or months on top of that. Consultants can be deployed in days. Third, consultants convert fixed labor costs into variable costs, giving companies more financial flexibility.

 

What Do Management Consultants Actually Do?

 

Management consultants work with clients to solve specific business problems. They collect and analyze data, develop strategic recommendations, and present their findings to senior leadership. Projects typically last three to nine months and involve teams of four to six consultants. Common project types include market entry strategies, cost reduction programs, post-merger integrations, and digital transformations.

 

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