Can You Be a Sole Trader and an Employee at the Same Time in the UK?

If you run (or are thinking about starting) a side business while also being on someone’s payroll, it’s completely normal to ask whether you can be a sole trader and an employee at the same time.

From a small business owner’s perspective, this question usually comes up in two common situations:

• You’re the founder and you also have a job elsewhere (especially in the early days when cashflow is tight).
• You employ staff and one of them wants to take on a side hustle as a sole trader (and you want to manage the risks properly).

The good news is that, in many cases, yes - someone can be both an employee and a sole trader in the UK. But the legal and practical “watch-outs” matter, because dual status can create real business risks around confidentiality, conflicts of interest, tax, and employment status.

Below, we’ll break down what you need to know, what to put in place, and how to protect your business from day one.

Is It Legal To Be Both Employed And A Sole Trader?

In most cases, it’s legal for a person to be an employee and also run a business as a sole trader at the same time. UK law doesn’t automatically prevent someone from having multiple income streams or working arrangements.

So if you’re asking, “can I be a sole trader and be employed?”, the legal answer is often “yes” - but it depends on the contract terms and the facts of the arrangement.

Why This Matters For Small Businesses

Even when it’s legal, dual status can create headaches for businesses if it’s not managed properly. For example:

• If your employee starts a competing sole trader business, you could face loss of clients, staff poaching, and misuse of confidential information.
• If your founder is employed elsewhere and breaches their employer’s restrictions, it can spill over into your business (including reputational risk or claims about IP ownership).
• If someone is treated like a contractor but behaves like an employee, there can be knock-on tax and employment law risks.

As a business owner, your goal is to get clarity early and document the arrangement properly.

What Should You Check Before Someone Runs A Sole Trader Side Business?

When someone asks whether they can be an employee and also run a sole trader side business, the most important thing is to check whether anything in their employment arrangement restricts it.

If you’re the employer, you should also check your own contracts and policies - because your documents are what you’ll rely on if a dispute comes up later.

1) Exclusivity Clauses And Secondary Employment Rules

Some employment contracts include an exclusivity clause (or a requirement to obtain consent before taking on outside work). These clauses are most common where:

• the employee is in a senior role,
• there’s a high risk of conflict of interest, or
• the business involves sensitive information or client relationships.

If you want to control this risk, it needs to be written clearly into the Employment Contract.

2) Conflicts Of Interest

Even without an express clause, employees generally owe duties to their employer (including a duty of fidelity). In plain English: they shouldn’t work against your business’s interests while employed by you.

So, if the side sole trader business:

• competes with you,
• targets your customers,
• uses your suppliers, pricing, or internal processes, or
• creates a “divided loyalty” problem,

that’s where disputes often begin.

3) Confidentiality And Use Of Business Information

Confidentiality is one of the biggest practical risks when an employee is also a sole trader. If they use your business information to build their own income stream, it may be a contractual breach and, depending on the facts, could become a serious dispute.

For many small businesses, it’s worth checking you have:

• a solid confidentiality clause in the employment contract,
• clear IP and work-product ownership terms, and
• policies that address acceptable use of systems and data.

It’s also common to back this up with internal policies like an Acceptable Use Policy so expectations are consistent across your team.

4) Restrictive Covenants (Non-Competes, Non-Solicits)

If your business depends heavily on client relationships or specialist staff, you may consider restrictive covenants. These can include:

• non-compete restrictions (limited and role-specific),
• non-solicitation of customers, and
• non-poaching of employees or contractors.

These clauses need to be reasonable and tailored - overly broad restrictions are harder to enforce.

How Does Tax Work If Someone Is Employed And Also A Sole Trader?

Legally, a person can have multiple roles, but the tax side needs to be handled properly. If you’re asking whether you can be employed under PAYE and also run a sole trader business, what you’re often really asking is: can I be paid through PAYE and also invoice clients?

Generally:

• Employment income is taxed through PAYE (with Income Tax and National Insurance deducted at source).
• Sole trader income is usually handled via Self Assessment, and they may need to register with HMRC as self-employed.

From a business owner’s perspective, what matters is making sure payments are structured correctly. If your business is paying someone as a contractor (invoicing) but the relationship looks like employment, you can create risk for both parties.

This section is general information only and isn’t tax advice. If you’re unsure how your situation should be treated, it’s best to speak to a qualified accountant or HMRC.

Keep Your Paper Trail Clean

If your business engages someone who is a sole trader (even if they’re also an employee elsewhere), you should ensure:

• they have a clear scope of work, deliverables, and payment terms,
• invoicing is consistent and properly documented, and
• you’re not accidentally treating them like an employee (for example, by controlling their hours and day-to-day work like staff).

It also helps to ensure your invoices meet basic requirements - especially if you want to stay organised and reduce payment disputes. Having a consistent invoicing process aligned with invoice requirements can save a lot of admin time later.

Founder Or Director Working A Job While Running A Sole Trader Business: What Should You Watch For?

If you’re building a business and also employed elsewhere, the “can I be a sole trader and be employed” question becomes especially important because the risk often sits with your current employer - and the consequences can affect your new venture.

1) Your Employment Contract May Affect IP Ownership

Many employment contracts include terms dealing with ownership of intellectual property created during employment. In some roles, this can be broad and may extend to things created outside normal working hours if they relate to the employer’s business or result from duties performed for the employer.

That can become complicated if:

• you’re building software, content, designs, or a product, and
• your day job is in the same field (or closely related).

This is one of those areas where getting tailored legal advice early is a smart investment - it’s much easier to address before your business grows.

2) Avoid Blurred Lines With Time, Equipment, And Contacts

Common triggers for disputes include:

• working on the side business during paid working hours,
• using the employer’s laptop, software, or confidential materials,
• approaching the employer’s clients or suppliers for your new venture.

Even if your intentions are good, blurred lines can look bad quickly if the relationship sours.

3) Check What Laws Your Business Must Follow

When you’re running lean, it’s easy to focus on sales and operations and forget compliance. But regardless of whether you’re “full-time” in your business, you still need to comply with the laws that apply to your industry - including contracts, consumer obligations, data protection, and advertising rules.

It’s worth having a simple checklist of what laws businesses have to follow so your side venture doesn’t accidentally become a legal headache.

If Your Employee Is Also A Sole Trader, How Do You Protect Your Business?

If you have staff, it’s increasingly common for employees to run side businesses. That’s not automatically a problem - but it does mean you should tighten your legal foundations.

Use Clear Contracts And Consistent Policies

Start with the basics:

• Employment contracts that cover confidentiality, conflicts, and outside work rules.
• Policies (like acceptable use and data handling rules) that are easy to follow in day-to-day operations.
• Onboarding and offboarding steps so confidential information, passwords, and customer lists are protected when someone leaves.

Be Clear About Contractor Vs Employee Relationships

Sometimes the situation is reversed - your “employee” might really be more like a contractor, or your contractor might be drifting into employee territory.

If you’re engaging sole traders for your business, make sure the relationship is documented properly. Depending on the role, this could be a Freelancer Agreement or a broader Service Agreement with the right scope, payment terms, IP ownership and confidentiality provisions.

The right agreement won’t just reduce disputes - it also helps show that you’re running your business professionally and consistently.

Don’t Forget Data Protection If They Access Customer Information

If your employee (or contractor) has access to customer data, the UK GDPR and the Data Protection Act 2018 come into play. That’s true whether they’re full-time, part-time, or “just helping out”.

Practical steps can include:

• limiting access to only what’s needed,
• making sure devices and accounts are secured,
• keeping policies and training up to date, and
• having the right external-facing documents in place.

If you collect personal data through your website or client onboarding, it’s also worth making sure you have a clear Privacy Policy that reflects what you actually do in the business (not what a random template says).

Key Takeaways

• In many cases, it’s legal in the UK to be both an employee and a sole trader at the same time.
• Whether it works in practice depends heavily on the employment contract, especially clauses on outside work, confidentiality, conflicts of interest and restrictive covenants.
• For founders working a job while building a business, key risks can include IP ownership, confidentiality, and blurred lines around time and equipment.
• For employers, the key is to protect your business with well-drafted contracts, clear policies, and consistent processes - especially where employees have access to confidential information or customer data.
• Where you engage sole traders (including staff with side businesses), use the right written agreements and keep invoicing and payment records organised.
• Data protection still applies whether someone is full-time, part-time, employed, or self-employed - so make sure your internal practices and external documents match what you do.

If you’d like help tightening your contracts or setting rules around employees with side businesses, we can help. Reach us at 08081347754 or team@sprintlaw.co.uk for a free, no-obligations chat.