How Much Does M&A Advisory Cost When Buying a Business?

Buying a business involves more than the purchase price. Buyers may also incur costs for M&A advisory, legal counsel, tax advice, due diligence, acquisition financing, notarial services and other specialist support.

The total transaction costs depend mainly on the size and complexity of the deal, the quality of the available information and the scope of the advisory work.

For small and mid-sized acquisitions in particular, it makes sense to budget these costs at an early stage and include them in the overall financing plan.

M&A advisory costs at a glance

The cost of buying a business goes beyond the purchase price. Buyers should also budget for M&A advisory, legal counsel, financial and tax due diligence, financing, notarial fees and, depending on the deal, other specialists.

There is no single percentage that works for every deal. What drives the cost is the size and complexity of the transaction, the number of entities, the quality of the data room, the depth of due diligence, contract complexity, financing and the agreed scope of advice.

Budgeting each workstream early is usually more reliable than applying a flat percentage to the purchase price.

Typical transaction costs when buying a business

What costs arise when buying a business?

Depending on the transaction, buyers may incur costs for:

• M&A or corporate finance advisory
• legal advice
• financial due diligence
• tax due diligence and tax structuring
• acquisition financing
• notarial services
• commercial, IT, ESG or other specialist due diligence
• W&I insurance, where relevant

The advisory team should reflect the size and risk profile of the transaction. A smaller mid-market acquisition may require a much leaner setup than a larger private equity process.

For budgeting purposes, the key question is which workstreams are actually required for the specific transaction.

How much does an M&A adviser cost?

The cost of an M&A adviser depends largely on the scope of the mandate.

On the buy side, an M&A adviser may assist with:

• identifying and approaching suitable targets
• valuation
• structuring an offer
• commercial negotiations
• coordinating the transaction process
• supporting the financing process

Common fee structures include fixed project fees, monthly retainers, success fees or a combination of these models.

Success fees are widely used in sell-side mandates. On the buy side, the fee structure also depends on whether the adviser is supporting one identified transaction or conducting a broader target search.

There is therefore no single percentage that accurately reflects M&A advisory fees across all transactions. Two acquisitions with the same purchase price can require very different levels of advisory work.

It helps to separate M&A or corporate finance advisers from legal counsel. Corporate finance advisers typically handle valuation, process and the commercial negotiation. Legal counsel handles due diligence, the transaction documents, signing and closing. Some tasks can overlap depending on the deal.

How much do legal fees for a business acquisition cost?

Legal fees for a business acquisition depend primarily on the scope of work handled by legal counsel.

Legal work on an acquisition usually falls into four phases:

1. LOI and structuring. Reviewing and negotiating the key commercial and legal terms and early structuring questions.
2. Legal due diligence. Reviewing the material legal risks of the target.
3. purchase agreement and negotiation. Drafting or negotiating the acquisition agreement, including purchase price mechanics, warranties, indemnities and closing provisions.
4. Signing and closing. Implementing the deal, conditions precedent, corporate documentation and completion.

The mandate may include:

• reviewing and negotiating the letter of intent
• legal due diligence
• transaction structuring
• drafting or negotiating the acquisition agreement
• preparing and supporting signing and closing
• reviewing closing conditions
• preparing corporate approvals and ancillary documents

In a share deal, the share purchase agreement, or SPA, is usually the central transaction document.

In an asset deal, individual assets and legal positions are transferred. The parties need to determine which contracts, receivables and liabilities are intended to transfer and whether third-party consents are required. Where the acquisition qualifies as a transfer of business under German law, employment relationships may transfer to the buyer by operation of law under section 613a of the German Civil Code.

Purchase price is only one factor affecting legal costs.

The number of entities, contractual complexity, employment matters, intellectual property, regulatory issues and the quality of the available documentation can all have a significant impact on the workload.

A well-prepared data room can make the review more efficient and reduce unnecessary legal work.

Hourly rates or fixed fees?

Many law firms bill M&A work based on time spent.

The client pays for the hours worked by the lawyers involved in the transaction. The final amount therefore depends on the actual workload generated by the deal.

A fixed fee can be suitable where the scope of work can be defined with sufficient clarity in advance.

Hourly billing reflects the actual workload but offers less cost certainty. A fixed fee gives more predictability where the scope is clear. The real question is whether the scope can be defined well enough before the work starts.

At CLIQ, we structure transaction mandates around clearly defined workstreams and fixed fees. This allows clients to understand the legal cost of the agreed scope before the engagement begins.

Learn more about our fixed-fee model on our Fixed Fees page.

How much does legal due diligence cost?

Legal due diligence is often one of the main components of the legal workstream.

Depending on the target, the review may cover:

• corporate documentation
• material customer and supplier agreements
• financing arrangements
• employment matters
• intellectual property and IT
• litigation
• licences and regulatory matters
• data protection
• real estate and lease agreements

The workload depends heavily on the target.

Relevant factors include the number of entities, employees and contracts, the quality of the data room and the agreed depth of review.

For many mid-market transactions, a risk-based approach is appropriate. The review can focus on matters that may affect the purchase price, transaction structure, closing or the buyer’s potential exposure after completion.

This allows the due diligence process to concentrate on risks that are economically relevant to the specific transaction.

What drives the cost of legal due diligence?

• number of entities
• size of the data room
• number of material contracts
• headcount and employment matters
• IP and IT setup
• regulatory requirements
• real estate and leases
• quality and completeness of the documents
• required depth of review

In mid-market deals, a risk-based scope keeps the review focused on matters that actually affect price, liability, deal structure or closing.

What other transaction costs can arise?

M&A and legal advice are only part of the overall cost of an acquisition.

Financial due diligence

Financial due diligence examines the financial performance and position of the target.

Areas of focus often include:

• revenue and earnings development
• EBITDA and normalisation adjustments
• working capital
• net debt
• cash flow
• quality and sustainability of earnings

The findings may affect valuation, purchase price and the purchase price mechanism.

Tax due diligence

Tax due diligence examines the target’s tax position and potential tax exposures.

Tax structuring is also an important part of many acquisitions. Relevant questions may include whether the transaction should be structured as a share deal or asset deal and how the acquisition vehicle and acquisition financing should be structured.

Acquisition financing

Where the acquisition is debt financed, additional financing costs may arise.

These can include:

• bank fees
• financing margins
• commitment fees
• costs of the financing documentation
• costs associated with security arrangements
• external adviser costs incurred by the financing bank, where these are payable by the buyer

These costs should be included in the financing model from an early stage.

Notarial costs

Certain transactions under German law require notarisation.

This applies in particular to agreements for the purchase and transfer of shares in a German limited liability company, or GmbH.

Additional corporate measures implemented as part of the transaction may also trigger notarial costs.

How high are the overall transaction costs?

There is no generally applicable percentage for the total cost of an M&A transaction.

Legal fees are only one part of the total transaction costs.

In a mid-market acquisition, external transaction costs can become significant. Purchase price alone is not a reliable indicator of the advisory workload.

The following factors are often more relevant:

• number of entities
• size of the data room
• quality of the available documentation
• number and complexity of material contracts
• regulatory requirements
• complexity of the purchase price structure
• financing requirements
• number of negotiation rounds
• cross-border elements
• transaction timetable

A business with a purchase price of EUR 10 million may require a similar level of advisory work to a business with a substantially lower purchase price.

A reliable budget therefore starts with defining the required workstreams and the scope to be covered by each adviser.

Purchase price ≠ financing need

Beyond the purchase price, buyers may need to plan for equity, bank debt, seller loans and transaction and financing costs. Additional liquidity or Working Capital needs after closing can also matter for the overall financing.

Example: which advisers does a buyer need?

Depending on the transaction, a buyer may require support across several areas.

M&A / Corporate Finance

Valuation, offer, commercial negotiation and process management.

Legal

LOI, legal due diligence, acquisition agreement, signing and closing.

Tax

Tax due diligence and acquisition structure.

Financial

Financial due diligence, EBITDA, Working Capital and Net Debt.

The number of separate advisory teams depends on the size and structure of the transaction. Certain workstreams may also be combined.

For smaller acquisitions, the scope should remain proportionate to the size and risk profile of the deal.

Do advisory costs differ between buy side and sell side?

Yes, because the work can differ.

On the buy side, the focus is usually on due diligence, acquisition structure, financing and protecting against identified risks in the purchase agreement.

On the sell side, preparing the sale process, vendor due diligence, the data room, negotiating the agreement and organising a clean exit can all be relevant.

The actual effort depends on the specific process.

What makes an acquisition expensive to advise on?

Certain features of a deal tend to increase the coordination effort:

• an incomplete or poorly structured data room
• several entities or countries
• many material contracts
• regulatory specifics
• complex purchase price provisions
• difficult financing
• many open DD issues
• additional negotiation rounds
• extensive seller rollovers or management structures
• a very short transaction timeline

None of these automatically leads to high costs, but each can increase advisory and coordination work.

Include transaction costs in the acquisition financing

The financing requirement for an acquisition is not limited to the purchase price.

A buyer financing a purchase price of EUR 3 million should also take into account potential advisory fees, notarial costs and financing costs.

Timing also matters.

A significant portion of the advisory costs is incurred during due diligence and contract negotiations. These costs therefore arise before closing.

Expected M&A advisory costs should be included in the financing plan from an early stage.

How can buyers control advisory costs?

A well-organised process makes transaction costs easier to manage.

Useful measures include:

• clearly defined review scopes
• a well-structured data room
• early coordination between legal, tax and finance advisers
• clear responsibilities
• focus on material risks
• early identification of potential dealbreakers
• transparent fee arrangements
• defining the due diligence scope upfront
• allocating responsibilities between legal, tax, FDD and M&A advisers
• avoiding overlap between advisers
• prioritising open issues early
• agreeing the fee model and possible scope extensions upfront

Due diligence should reflect the specific risk profile of the target.

Legal and tax issues identified after closing can have significant economic consequences. A focused review before the acquisition allows the buyer to identify those issues early and address them through pricing, transaction structure or contractual protection.

Controlling costs does not mean skipping reviews. It means spending advisory time where it matters commercially.

How much does legal M&A advice cost at CLIQ?

We advise buyers and sellers throughout the M&A process.

Our work can include:

• letter of intent
• legal due diligence
• tax due diligence
• transaction structuring
• acquisition agreement
• signing
• closing

For clearly defined transaction packages, we work with fixed fees.

This gives clients clarity on the legal fees for the agreed scope before the engagement begins.

Learn more about our Fixed Fees and M&A legal services.

Frequently asked questions about M&A costs

How much does a lawyer cost when buying a business?

The cost depends on the size and complexity of the transaction and the agreed scope of work. A mandate limited to negotiating the acquisition agreement will involve a different workload from a full transaction mandate covering the LOI, legal due diligence, signing and closing. Legal fees may be billed on an hourly basis or agreed as a fixed fee.

How much does an M&A adviser cost?

An M&A adviser may charge a retainer, fixed project fee, success fee or a combination of these models. The level of fees depends on the size of the transaction and the scope of the mandate.

What costs arise in addition to the purchase price?

Additional costs may include legal advice, financial and tax due diligence, M&A advisory, financing costs, notarial costs and fees for other specialist advisers.

What percentage of the purchase price should be budgeted for transaction costs?

A single percentage is of limited use. Fixed advisory costs represent a larger proportion of the purchase price in smaller transactions. A more reliable approach is to budget the required workstreams individually before the process begins.

Which advisory costs arise before closing?

Much of the advisory work happens during the LOI, due diligence, structuring, financing and negotiation phases. These costs can therefore fall due before the deal completes.

Are legal due diligence and the purchase agreement covered by the same fee?

That depends on the fee arrangement and the agreed scope. Before the engagement starts, it should be clear which phases and work steps the fee covers.

What is the difference between an M&A adviser and an M&A lawyer?

M&A or corporate finance advisers mainly handle commercial matters such as valuation, process management and negotiation. M&A lawyers handle the legal review and implementation of the deal, including due diligence, drafting, signing and closing.

Are transaction costs tax deductible?

The tax treatment of transaction costs depends on the nature of the costs and their connection with the acquisition. Our separate article on the tax treatment of deal costs provides a more detailed analysis.

Conclusion

Buying a business involves transaction costs in addition to the purchase price. These may include M&A advisory, legal advice, due diligence, financing and notarial costs.

The overall amount depends heavily on the target, the transaction process and the agreed scope of work.

Buyers can improve cost visibility by defining the required workstreams early, allocating responsibilities clearly and agreeing the fee structure before substantial work begins.

For legal M&A work, fixed fees can provide additional cost certainty. The agreed scope and the corresponding legal fees are established before the mandate starts.

Learn more about our M&A legal services and our Fixed Fees.