How third-party software introduces cyber risk for UK SMEs

Third-party software can save time, reduce development effort, and help a small business move faster. That is the upside. The downside is that every external tool, app, plugin, library, or managed service can also bring cyber risk into your business.

For UK SMEs, this matters because the business usually keeps the responsibility even when the software is bought in. If a supplier has weak security, a poor update process, or a service outage, the impact can quickly become your problem. That can mean lost sales, interrupted operations, customer complaints, and damage to trust.

The good news is that you do not need a large security team to manage this well. Most SMEs can reduce the biggest risks with a few practical checks, sensible buying questions, and regular reviews.

What third-party software means in practice

Third-party software is any software or service you rely on that you did not build yourself. In day-to-day business, that often includes:

• Cloud applications for finance, customer management, payroll, or marketing
• Website plugins and add-ons
• Software libraries used by your developers to build products faster
• Managed services provided by an external supplier
• Remote support tools used by IT providers
• Automation tools that connect different systems together

SMEs rely on these tools because they are usually cheaper and faster than building everything from scratch. That is a sensible business decision. The risk appears when the business assumes the supplier has taken care of everything, or when no one keeps track of what has been installed, who can access it, and what data it can reach.

How third-party software creates business risk

Third-party software creates risk in three main ways: it can expose data, disrupt services, or open hidden access paths into your environment.

Data exposure, service disruption, and hidden access paths

If a supplier stores customer records, employee details, payment information, or other sensitive data, a weakness in their system can expose your information. Even if the breach happens at the supplier, your business may still face the operational and reputational fallout.

Service disruption is another common issue. If a cloud service goes down, your team may not be able to process orders, issue invoices, access files, or communicate with customers. For a small business, even a short outage can have a noticeable financial impact.

Hidden access paths are often overlooked. A supplier may have administrator access, a support account, an integration token, or a connection into your systems that was created months ago and never reviewed. If that access is not tightly controlled, it can become a route for misuse or accidental exposure.

Reputation, customer trust, and operational impact

The direct cost of a software issue is only part of the story. Customers and partners often care less about whose fault it was and more about whether the business stayed in control.

A serious third-party issue can lead to:

• Lost customer confidence
• Extra support calls and complaints
• Delayed deliveries or missed deadlines
• Time spent on manual workarounds
• Management distraction from core business priorities

For many SMEs, the hidden cost is time. Staff end up chasing suppliers, resetting access, checking logs, or explaining delays instead of doing productive work.

The most common risk areas to watch

Most third-party software risk falls into two broad areas: weak supplier security and dependency problems.

Weak supplier security and poor access control

A supplier may have weak password practices, limited monitoring, or poor internal controls. You may not see this directly, but you can often spot warning signs during procurement or renewal.

Access control is equally important. If too many people have administrator rights, if old accounts are left active, or if support access is not reviewed, the risk rises. The more powerful the access, the more important it is to know exactly who has it and why.

Outdated components, insecure updates, and dependency sprawl

Modern software often depends on other software underneath it. That means one product may rely on many smaller components, each with its own update cycle and security posture. This is sometimes called dependency sprawl, which simply means the number of moving parts keeps growing.

Problems can appear when:

• A supplier uses outdated components
• Updates are rushed or poorly tested
• Security fixes are delayed
• One product depends on another product that depends on another service

For an SME, the practical issue is simple: the more layers there are, the harder it becomes to understand where the real risk sits.

Questions to ask before you buy or renew software

You do not need a technical deep dive for every purchase. You do need a short set of questions that help you understand the business risk before you commit.

What data does the supplier handle and where is it stored?

Start with the basics. Ask what data the supplier will handle, where it is stored, who can access it, and whether it is shared with any other parties. If the software touches customer, employee, financial, or confidential business information, treat it as higher risk.

Also ask whether the data is stored in the UK, the wider European region, or elsewhere. Location is not the only factor, but it helps you understand where your information may travel and what support arrangements are in place.

How are updates, support, and incident notifications managed?

Software is only as safe as its update process. Ask how often the supplier releases fixes, how urgent security updates are handled, and whether you will be told promptly if there is a serious issue.

You should also know:

• How support requests are handled
• Whether support staff need access to your data or systems
• How the supplier will notify you of outages or security incidents
• What happens if the supplier is bought, sold, or stops trading

These questions are not about being difficult. They are about avoiding surprises later.

Simple checks SMEs can carry out without specialist tools

Many of the most useful checks are administrative rather than technical. They can be done by a manager, business owner, or office lead with help from IT where needed.

Review permissions, user accounts, and admin access

Check who has access to each system and whether that access is still needed. Remove old accounts, especially for former staff, contractors, and suppliers. Limit administrator access to the smallest number of people needed to do the job.

Where possible, use separate accounts for normal work and for administration. That reduces the chance of a mistake causing wider damage.

Keep a basic register of suppliers, owners, and renewal dates

Many SMEs lose track of software because it is bought by different teams over time. A simple register can make a big difference. It should record:

• The software name
• The supplier
• The business owner
• What data it handles
• Who has access
• Renewal or review date
• Any known risks or concerns

This does not need to be a complex system. A well-maintained spreadsheet is often enough to start with.

How to reduce risk after the software is in place

Buying software is only the first step. Risk changes over time, so the controls need to be reviewed regularly.

Limit access, remove unused accounts, and review settings regularly

Check permissions at least quarterly for important systems, and more often for anything that handles sensitive data or supports key operations. Remove unused accounts, review administrator rights, and confirm that settings still match the way the business actually works.

It is also worth checking whether staff have enabled extra features or integrations that were not part of the original approval. Small changes can create new exposure without anyone noticing.

Plan for exit, backups, and alternatives if the supplier fails

Every important supplier should have an exit plan. If the service stops, becomes too expensive, or no longer meets your needs, how will you move away from it?

At a minimum, think about:

• How you would export your data
• How long it would take to switch to another service
• Whether you have backups of critical information
• What manual workaround you would use during a disruption

This is especially important for software that supports sales, finance, customer service, or operations. If the supplier fails, your business should still be able to function in a reduced form.

When third-party software should trigger a deeper review

Not every tool needs the same level of scrutiny. Some software is low risk and easy to replace. Other systems deserve more attention.

Carry out a deeper review when the software:

• Handles sensitive or regulated data
• Supports a business-critical process
• Has administrator access into your systems
• Connects to many other tools
• Has unclear security practices
• Is supplied by a company with limited transparency

In those cases, it is sensible to ask for more detail before purchase or renewal. That may include a security questionnaire, evidence of access controls, or a clearer explanation of how incidents are handled.

A practical checklist for SME decision-makers

Use this as a simple starting point.

Before purchase

• Confirm what data the software will handle
• Ask where the data is stored and who can access it
• Check how updates and security fixes are managed
• Ask how you will be told about incidents or outages
• Confirm who owns the system inside your business
• Record the renewal date and review point

During ongoing use

• Review user accounts and permissions regularly
• Remove accounts that are no longer needed
• Check that administrator access is still justified
• Review supplier performance and incident history
• Test how you would leave the service if needed
• Keep backups or exports of critical data

These steps will not remove every risk, but they will reduce the chance of a supplier problem becoming a business problem.

Final thought

Third-party software is part of normal business life. The aim is not to avoid it altogether. The aim is to use it with your eyes open, so you understand what it adds to your risk, what it protects, and what it could disrupt.

If you want help reviewing supplier risk, tightening software controls, or building a more practical approach to secure development and software assurance, speak to a consultant.

Frequently asked questions

What counts as third-party software for a UK SME?

Third-party software is any tool or service you rely on that you did not build yourself. That includes cloud applications, website plugins, software libraries, managed services, remote support tools, and automation tools that connect systems together. The key point is that if your business depends on it, it can also introduce risk into your environment.

Why can third-party software become my business's problem if the supplier is at fault?

Even when the issue starts with the supplier, the impact often lands on your business. A weak update process, poor security, or a service outage can affect customer data, interrupt operations, and create extra work for your team. Customers and partners usually care most about whether you stayed in control and kept services running.

What should I ask before buying or renewing software?

Start by asking what data the supplier will handle, where it is stored, who can access it, and whether it is shared with other parties. It is also sensible to ask how updates are managed, how you will be told about outages or security incidents, and what happens if the supplier is bought, sold, or stops trading. These questions help you judge the business risk before you commit.

How do hidden access paths create risk in third-party tools?

Hidden access paths can include administrator access, support accounts, integration tokens, or old connections into your systems that were created and never reviewed. If that access is not tightly controlled, it can be misused or exposed by accident. Regularly checking who has access and why is a practical way to reduce that risk.

What is dependency sprawl and why does it matter?

Dependency sprawl means software relies on many other components and services underneath it, sometimes in layers. The more moving parts there are, the harder it becomes to see where risk sits and whether updates are being handled properly. For an SME, the practical response is to keep track of what is installed and review it regularly.