Many people – women in particular – start their business on a small scale, often part-time. Keeping a day job while you build a venture on the side makes practical sense: the mortgage or rent still has to be paid, and it often takes longer than you expect for the money to flow in. According to recent Office for National Statistics figures, around 4.4 million people in the UK are now self-employed, and a sizeable share of them began by running a business alongside paid employment.

But this dual existence is not an easy path. I know because I have lived it, both with my own business and while helping a friend launch hers.

For six short but very long weeks, I became a front-of-house assistant by day in my friend’s new wellbeing studio in Leeds and a business owner by night. It was a full and tiring life. Yet there were moments of real fun – such as when an elderly client told me I was doing a great job and, assuming I was a temp looking for permanent work, touched my arm and said she was sure I’d be “snapped up” and not to worry. Good to know.

Working the two roles was a stretch, but I learned a great deal. I was reminded how much I like working with people. When you work from home, the four walls can close in and you can tire of your own company.

Most of all, I watched my friend blossom. As she gained confidence not only in her ability to run a business but in the fact that people actually wanted to pay for her services, her whole energy changed. We all have doubts, especially at the beginning when everything is new.

Check the legal and financial basics first

Before you take on your first paying customer, make sure the foundations are solid. Start by reading your employment contract: many UK employers include clauses about outside business interests, confidentiality, intellectual property and non-compete restrictions. If your side business could conflict with your day job, speak to your employer or HR team before you begin.

You must also tell HMRC about any self-employed income. If your trading income is above the £1,000 tax-free trading allowance, you will need to register for Self Assessment and file a tax return each year. You will also usually pay Class 2 and Class 4 National Insurance contributions on your profits, so factor these into your cash-flow forecasts. If you decide to trade through a limited company, you must register with Companies House and understand your responsibilities around Corporation Tax and payroll. Good record-keeping from day one will save you hours of stress later.

It is also worth checking whether you need insurance – public liability, professional indemnity or product liability – and whether you need any licences or permits for your particular sector. A little homework now prevents expensive surprises.

When is the right time to make the leap?

One of the biggest decisions is when to move away from the comfort and cushioning of your salary and leap into your business full-time. How do you know when the time is right?

While it is often said that if you pursue your passion the money will follow, that is not always the case. So take a long, hard look at your finances and your realistic ability to make ends meet before handing in your notice.

Do the maths. Work out what you need to live on each month, including rent or mortgage, council tax, utilities, food, transport, childcare and any debt repayments. Then look at what you have saved. Most advisers recommend having at least six months’ worth of essential living costs set aside, otherwise you put yourself at serious financial risk.

Study your business data. How many clients or customers do you have? What is their average spend? How many are repeat buyers? Do you have the processes in place to handle growth? Do you have a marketing plan to promote your business with more vigour than in the past? And, perhaps most importantly, do you have the tenacity to stick with it when orders are slow?

Can you live with ambiguity?

If you are staying in the same industry but moving towards freelance work, find out whether your current employer would be willing to give you a contract. That is what I did when I started my consulting business. They knew my work and what I could deliver, and it gave me a valuable kick-start.

Be aware, though, that if you operate through a limited company, you need to understand the UK’s IR35 and off-payroll working rules. These determine whether you are genuinely self-employed for tax purposes. Getting the status wrong can be costly, so seek advice if you are unsure.

Over time, my own consulting practice bank-rolled a women’s enterprise project I ran on the side. The consulting generated more revenue, but the project was where my heart was and where I could see I was making a difference. Two years down the road, I packed in the consulting to focus all my energies on the business that had become my passion.

It is that passion that will move you from the safety of your job to focusing on your own business full-time

The day job, while providing a safety net, can seem humdrum in comparison to running your own venture. You need to pay attention to what fires you up and gets you out of bed in the morning. It is that energy, passion and love of what you do that will get you through the challenges ahead and help you build a life that truly matters.

Starting your business on the side is one of the smartest ways to test an idea, build a customer base and reduce risk. With the right UK groundwork – a clear financial plan, compliance with HMRC and your employment contract, and a marketing strategy that can scale – you can make the leap with confidence when the time is right.