How to Conduct Financial Due Diligence When Buying a UK Law Firm

Why Financial Due Diligence Matters for Solicitors Buying a Firm

Buying an established law firm can be the fastest route to growing your practice. But the goodwill price tag often masks hidden liabilities. A thorough financial due diligence process is the only way to confirm you are paying a fair price for a solvent, compliant business.

As a solicitor, you already know that legal due diligence examines contracts, litigation risk, and regulatory compliance. Financial due diligence is different. It focuses on the numbers: the quality of earnings, the accuracy of the balance sheet, the tax position of the seller, and the condition of work in progress (WIP).

This guide is written for solicitors and law firm partners who are considering buying a practice. It covers the key areas you need to examine, the documents you must request, and the red flags that should make you walk away.

Start With the Seller Accounts Review

The seller accounts review is the foundation of any law firm purchase. You need at least three years of full statutory accounts, plus management accounts for the current financial year. Do not rely on a single year's figures. A law firm can look profitable in year one and be insolvent by year three.

Request the following documents from the seller:

• Full statutory accounts (profit and loss, balance sheet, notes) for the last three financial years.
• Management accounts for the current year, month by month.
• Tax computations and HMRC correspondence for the last three years.
• Copies of the partnership deed or LLP agreement.
• The most recent SRA accountant's report.
• PII renewal documents and claims history.
• Details of any outstanding loans, hire purchase, or lease agreements.

Compare revenue trends year on year. Is the firm growing, flat, or declining? If revenue is dropping, find out why. It could be a retiring partner taking their clients elsewhere, or a shift in the local market. A declining firm may still be a good buy, but only at the right price.

Look at the gross profit margin. A typical high-street law firm should have a gross margin of 60-75%. If the margin is below 50%, the firm may be pricing work too cheaply or carrying too many non-chargeable staff. Check the ratio of fee-earner salaries to total overheads. If overheads are eating up more than 40% of gross profit, the firm may be inefficient.

Examine the balance sheet for hidden liabilities. Common issues include:

• Undrawn partner profits that have been left in the business as loans.
• Large director's loan accounts (for limited company structures) that the seller expects you to repay.
• Deferred tax liabilities on goodwill or fixed assets.
• Client account shortfalls that have not been corrected.

A clean seller accounts review gives you confidence that the firm's reported profits are real and sustainable.

WIP Review: The Most Misunderstood Asset

Work in progress (WIP) is often the largest asset on a law firm's balance sheet after goodwill. But WIP is not cash. It is time that has been recorded but not yet billed. A WIP review is essential because overvalued WIP can make a firm look far more valuable than it really is.

Ask the seller for a detailed WIP schedule broken down by matter. Each matter should show:

• The fee-earner responsible.
• The date the work was done.
• The total WIP value.
• The likelihood of billing (e.g., 100% certain, 80% likely, or contingent on an event).

Look for WIP that is more than six months old. Aged WIP may be difficult to bill, especially if the matter has gone quiet or the client has complained. Some firms carry WIP for years without ever billing it. That is not an asset. It is a problem you will inherit.

Check the firm's billing policy. Do they bill monthly, at key stages, or only on completion? Firms that bill regularly tend to have lower WIP and better cash flow. Firms that bill only on completion often carry large WIP balances that may never convert to cash if the matter stalls.

Compare WIP to the firm's annual fee income. A healthy ratio is WIP of no more than 10-15% of annual turnover. If WIP is 25% or more, the firm may be under-billing or carrying dead matters.

Also check how the seller values WIP for tax purposes. Under FRS 102, WIP must be recognised on an earnings basis once revenue is reliably measurable. Some firms use a conservative approach, valuing WIP at cost. Others use a more aggressive approach, valuing WIP at full charge-out rates. The difference can be significant. Make sure you understand which method is used and adjust your offer accordingly.

A thorough WIP review should be part of your standard firm DD checklist. Do not skip it.

Check SRA Compliance and the Client Account

As a solicitor, you know that SRA compliance is non-negotiable. A law firm with a history of client account breaches can be a regulatory minefield. You could inherit the liability, including fines, costs, and reputational damage.

Request the following SRA-related documents:

• The last three SRA accountant's reports. Look for qualified reports or reports that note breaches of the SRA Accounts Rules.
• Any correspondence from the SRA about compliance issues, including fines or warning notices.
• The firm's COFA and COLP details. Are these roles held by competent people? If the COFA has changed frequently, that is a red flag.
• Client account reconciliations for the last 12 months. Check that reconciliations were done at least every five weeks, as required by Rule 8.3.
• A list of any residual client balances that have not been returned to clients.

If the firm has a history of client account breaches, you need to decide whether the risk is worth taking. Some breaches are minor and easily fixed. Others, such as using client money to pay office account bills, are serious and may indicate a systemic problem.

You should also check whether the firm holds any client money that is subject to the SRA's de minimis exemption. If the firm held more than £10,000 at any point during the year, it must have an accountant's report. If it did not, that is a compliance failure.

For more detail on what to look for, read our guide on SRA Accounts Rules essentials.

Review the Partner and Staff Tax Position

The tax position of the selling partners can affect the deal structure and your future tax liabilities. You need to understand how the firm is structured and how the partners are taxed.

If the firm is a partnership or LLP, each partner is taxed on their share of the profits at their personal marginal rate. The partnership itself does not pay corporation tax. Check the partnership deed or LLP agreement for profit-sharing ratios, capital contribution requirements, and any special provisions for retiring partners.

Ask for the partners' tax returns for the last two years. Look for any unusual items, such as:

• Large capital gains from previous asset sales.
• Claims for capital allowances that may be clawed back.
• Undrawn profits that have been left in the business and may be taxed on the partners personally.
• Any outstanding HMRC liabilities or time-to-pay arrangements.

If the firm has salaried members (under the FA 2014 Salaried Member Rules), check whether PAYE has been applied correctly. A salaried member who meets all three conditions (disguised salary, limited influence, insufficient capital contribution) should be treated as an employee for tax purposes. If the firm has not operated PAYE, there could be a significant tax liability waiting for you.

For limited company law firms, check the corporation tax position. Has the company paid the correct rate (19% or 25% depending on profit level)? Are there any deferred tax liabilities on goodwill or fixed assets? A deferred tax liability on goodwill acquired before April 2019 can be substantial.

Our partnership vs LLP take-home calculator can help you model the tax impact of different structures.

Assess the Quality of Earnings

Not all profit is equal. A law firm that makes £500,000 a year from a retiring partner's personal connections is less valuable than a firm that makes £300,000 from institutional clients and repeat business. You need to assess the quality and sustainability of the earnings.

Ask for a breakdown of revenue by:

• Practice area (conveyancing, litigation, family, commercial, etc.).
• Client type (individual, SME, corporate, public sector).
• Fee-earner (how much revenue does each fee-earner generate?).
• Recurring vs one-off work.

If more than 40% of revenue comes from one client or one fee-earner, the firm is vulnerable. That client could leave, or that fee-earner could retire or move to another firm. You should discount the earnings from concentrated sources when valuing the firm.

Also check the firm's client retention rate. A firm that retains 80% of its clients year on year is far more valuable than one that loses 30% of clients annually. Ask for a list of the top 20 clients and how long they have been with the firm.

Look at the firm's marketing spend. If the firm spends very little on marketing but has a steady stream of referrals, that is a positive sign. If the firm spends heavily on Google Ads to generate leads, those leads may dry up if you change the marketing strategy.

Review the PII Position

Professional Indemnity Insurance (PII) is a major cost for any law firm. You need to understand the firm's claims history and how it affects the premium.

Request the following:

• The last three years of PII renewal documents, including the premium paid.
• A full claims history, including any notified circumstances that have not yet become claims.
• Any run-off cover that has been purchased for retired partners.

If the firm has a history of claims, the premium may be significantly higher than the market average. Some firms with poor claims records struggle to find cover at all. You need to factor the true cost of PII into your financial model.

Also check whether the firm's PII policy covers the new ownership structure. Some policies have change-of-control clauses that require the insurer's consent. If the insurer refuses to cover the new entity, you may need to find alternative cover at short notice.

For more on this topic, see our guide on PII tax treatment for solicitors.

Build Your Firm DD Checklist

A structured firm DD checklist ensures you do not miss anything. Here is a summary of the key areas to cover:

• Financial accounts: Three years of statutory accounts, management accounts, tax computations.
• WIP review: Detailed WIP schedule, aged WIP analysis, billing policy.
• SRA compliance: Accountant's reports, client account reconciliations, COFA/COLP records.
• Tax position: Partner tax returns, corporation tax (if limited company), deferred tax liabilities.
• Earnings quality: Revenue concentration, client retention, fee-earner dependency.
• PII: Claims history, premium costs, run-off cover.
• Staff and pensions: Employment contracts, auto-enrolment compliance, any defined benefit pension liabilities.
• Property and leases: Lease terms, dilapidations obligations, any rent review clauses.
• IT and data: Case management system, data protection compliance, cybersecurity insurance.

Work through each item systematically. If you are not comfortable reviewing the financials yourself, engage a solicitor accountant who specialises in law firm transactions. Our team at Accounts for Lawyers provides practice valuation services and can support you through the due diligence process.

Common Pitfalls to Avoid

Even with a thorough DD process, buyers can make mistakes. Here are the most common ones:

Overvaluing goodwill. Goodwill is the premium you pay above net asset value. For a typical high-street law firm, goodwill is worth 1-3 times normalised profit. Specialist firms with strong brands may command a higher multiple, but be realistic. Do not pay for goodwill that is tied to a retiring partner who will not stay on.

Ignoring the WIP write-down. Sellers often value WIP at full charge-out rates. In reality, not all WIP will be billed. Negotiate a WIP write-down of 10-20% to reflect the risk of non-billing.

Assuming all clients will stay. Clients are not assets you can buy. They are people who choose to instruct a solicitor. After the sale, some clients will leave. Factor in a 10-20% client attrition rate in your financial projections.

Overlooking the partner pension liability. Some older partners have large pension contributions that have been funded by the firm. If the partner retires, the firm may lose that funding, but the liability may still exist. Check the partnership deed for any ongoing pension obligations.

Final Thoughts

Financial due diligence is not optional when buying a law firm. It is the process that protects you from overpaying, inheriting hidden liabilities, or buying a business that is not viable. A structured firm DD checklist, a thorough seller accounts review, and a careful WIP review are the three pillars of a successful purchase.

If you are considering buying a law firm and want expert support, speak to our team. We are solicitor accountants who understand the unique financial and regulatory challenges of law firm transactions. Contact us to discuss your situation.