Technology Due Diligence for PE: A Buyer's Guide

Technology due diligence for private equity is not the same as an IT audit. The goal is different, the timeline is different, and the questions are different. Yet it's surprising how often PE deal teams treat these two things as interchangeable, and then wonder why the report they receive doesn't help them make a better investment decision.

I've been on both sides of this. Twenty-two acquisition integrations inside a PE-backed group, plus advisory work on £300m+ of PE and VC investment decisions. The deals that went well were almost always the ones where the tech DD was done for the deal, not in spite of it.

This guide is for PE deal teams, operating partners, and CFOs who want to understand what good technology due diligence for PE looks like, when to run it, and how to avoid the most common mistakes.

What Makes PE Tech DD Different

A standard IT audit asks: does this technology work, is it secure, is it documented?

Those are reasonable questions, but they're the wrong starting point for a PE deal. The questions that matter in a PE context are:

• Can this technology support the growth plan in the investment thesis?
• What will it cost to integrate this business into the group, or prepare it for a future exit?
• Where is the key person risk, and how exposed is the business if one or two engineers leave?
• Is the technical debt a manageable backlog or a structural problem that will slow every growth initiative?
• Has the business been buying in capability it should have built, or building things it should have bought?

These are not IT questions. They are investment questions with a technology dimension. Getting them right requires someone who understands both the deal context and the engineering reality underneath it.

What PE-Specific Tech DD Covers

Scalability under the growth plan. The investment thesis makes assumptions about growth. Good tech DD stress tests those assumptions against the current architecture. If the thesis is £5m ARR to £15m, the question is whether the platform can carry that without a re-platforming cost that should be in the deal model.

Integration readiness. If the acquisition is a bolt-on, the technology has to connect to the group. That means APIs, data model compatibility, and identity and access management consolidation. The cost and timeline for this work varies enormously, and it is rarely visible in the SPA without a specialist review.

Key person risk. In many software businesses, the entire engineering function sits in one or two heads. If those people leave after close, the business can lose years of institutional knowledge. Good tech DD maps the bus-factor explicitly and flags retention risk as a deal condition where it is material.

Tech debt versus runway. All software has technical debt. The question is whether it is normal and manageable, or structural and compounding. Structural tech debt means every new feature takes twice as long and costs twice as much to build. This needs to be visible in the investment model, not discovered six months after close.

Build versus buy decisions. The historical build versus buy decisions a team has made reveal a lot about their judgment. A team that has built everything in-house when mature SaaS tools existed is often sitting on high maintenance cost and low scalability. A team that has bought everything may have a patchwork of tools with no coherent data model.

When in the Deal Cycle to Run Tech DD

Pre-LOI. A lightweight red flag review before the letter of intent is signed is often the highest-value engagement. It takes a few days, covers management interviews and document review, and surfaces anything that would change the terms or the decision. This is not a full assessment, but it prevents the worst surprises.

Confirmatory DD. After LOI, a full technology due diligence assessment runs alongside legal and financial DD. This typically takes one to two weeks, produces a formal report, and feeds directly into SPA negotiations, price adjustments, and integration planning. This is where the full cost of ownership picture is built.

Post-close assessment. Sometimes tech DD was not done, or was done superficially, and the deal has already closed. A post-close assessment in the first 30 days gives the operating partner and deal team a clear picture of what was actually bought, and where the integration priorities should sit.

Common PE Tech DD Mistakes

Treating it as a checkbox. The most common mistake is commissioning a tech DD report and then not using it. The report goes into the data room, the findings do not feed into the deal model, and the integration team discovers the same issues six months later at three times the cost to fix them.

Running it too late. Tech DD commissioned in the final week before signing is almost useless. There is no time to investigate findings, negotiate on them, or adjust the model. The pressure to complete the deal means findings get sanitised or deprioritised. Run it in confirmatory DD, not at the last moment.

Not connecting findings to the value creation plan. A tech DD report that identifies risks without connecting them to the 100-day plan or the deal cost is a missed opportunity. Every material finding should have an owner, a cost estimate, and a place in the integration roadmap.

Using the wrong reviewer. A generalist IT consultant will assess whether the systems work. A reviewer with M&A experience will tell you whether the systems work for this deal. Those are different questions, and they require different expertise.

What a Good Tech DD Report Looks Like for a Deal Team

A report that's useful to a PE deal team has five components.

Executive summary. One to two pages. Key findings, overall risk rating, and the top three things the deal team needs to know before signing. If the deal team has to read the full report to understand the investment implications, the report has failed.

Risk matrix. A structured view of identified risks, rated by severity and proximity. Severity is the potential impact on the investment. Proximity is how soon the risk could crystallise. This lets the deal team and operating partner triage quickly.

Remediation cost. For every material risk, an order-of-magnitude cost estimate. This does not need to be a precise budget. It needs to be accurate enough to decide whether it belongs in the deal model or the integration budget.

Integration implications. A specific section on what integration will require: which systems need to connect, what the estimated cost and timeline is, and what the dependencies are. This feeds directly into the 100-day plan.

Team and capability assessment. A view of the engineering team: strengths, gaps, and key person dependencies. This informs both the retention strategy and the hiring plan for the integration window.

How I Can Help

I run technology due diligence for PE deals through techdd.co.uk. Engagements range from a pre-LOI red flag review to a full confirmatory DD assessment with integration planning included.

If you'd like to discuss a specific deal or understand what a technology due diligence engagement would cover, I also offer advisory services for PE firms and operating partners. You can find out more about my background on the about page.

If you're researching the topic further, the posts on red flags in technology due diligence and the post-acquisition integration playbook are the most relevant starting points.

Frequently Asked Questions

How long does technology due diligence take in a PE deal?

A pre-LOI red flag review typically takes three to five days. A full confirmatory DD assessment runs one to two weeks, depending on the complexity of the business and the level of access available. Both timelines assume reasonable cooperation from management and access to documentation.

Who should commission the tech DD, and who should receive it?

The PE firm commissions it, typically through the deal team or operating partner. The primary audience is the deal team and operating partner. A summary version is sometimes shared with the portfolio company's incoming management team after close, but the full report stays with the acquirer.

How much does technology due diligence cost for a PE deal?

For mid-market deals in the £10m to £100m EV range, a full tech DD engagement typically costs between £8,000 and £25,000 depending on scope, complexity, and the seniority of the reviewer. A pre-LOI red flag review is at the lower end of that range.

What's the difference between a technical audit and technology due diligence for PE?

A technical audit assesses whether systems are working, secure, and documented. Technology due diligence for PE frames every finding in the context of the deal: what does this mean for the investment thesis, the integration plan, the deal model, and the exit. The output of a tech audit is a list of issues. The output of PE-specific tech DD is investment-relevant insight.

Can tech DD be done on a compressed timeline if the deal is moving fast?

Yes, with trade-offs. A focused assessment over two to three days can cover the highest-risk areas and produce a usable executive summary. It will not give you the full picture, but it is significantly better than going in blind. If the deal is moving fast, the priority is identifying anything that would change the decision or the price, not a comprehensive inventory of every technical issue.