Part-time entrepreneurship: Tips for freelancers (‘zzp’ers’) alongside employment

Check your employment contract for ancillary activities (‘nevenwerk’)

Before you enthusiastically get started, it’s smart to check your employment contract. Some contracts contain conditions that restrict ancillary activities (‘nevenwerkzaamheden’) or for which you must request prior permission from your employer. Read your contract carefully and, if necessary, discuss it with your employer. Transparency on this is often the best way to prevent surprises or hassle in the future. A good relationship with your employer is essential if you are going to be a part-time entrepreneur.

Taxation for freelancers (‘zzp’ers’) alongside employment

As a part-time freelancer, you will have income from two sources: your employment and your business. For Income Tax (‘Inkomstenbelasting’), these incomes are added together. This means your total income will be higher, which affects the tax you pay. Because no tax has been withheld on your income from your business, you pay this retrospectively with your annual tax return.

Simple example: Suppose you earn €30,000 in employment and €10,000 as a freelancer. Your total income for the Belastingdienst (Dutch Tax Authorities) will then be €40,000. The tax you pay on this will be calculated on this combined amount.

Hour criterion (‘urencriterium’) and deductions (‘aftrekposten’): is it feasible?

As a freelancer (‘zzp’er’), you can benefit from attractive tax advantages, such as the self-employed deduction (‘zelfstandigenaftrek’) and start-up deduction (‘startersaftrek’). To qualify for these, you must be considered an entrepreneur for Income Tax purposes and you must meet the hour criterion (‘urencriterium’): you must spend at least 1,225 hours per calendar year on your business. This amounts to an average of approximately 24 hours per week.

Do indirect hours count? Absolutely! Not only the hours you spend directly on clients count, but also indirect hours. This includes:

• • Keeping administration
  • Marketing and acquisition
  • Setting up your website
  • Networking
  • Further training relevant to your business

Please note: If you also work in employment, you must work at least as many hours in your business as you do in employment to claim the self-employed deduction. If you work 1600 hours in employment in a year, you must also spend 1600 hours on your business to claim the self-employed deduction. However, if you meet the conditions for the start-up deduction (e.g., not being an entrepreneur for at least one of the past five years), the 1225-hour rule always applies.

If you do not meet the hour criterion, you may still be entitled to the SME profit exemption (‘MKB-winstvrijstelling’). This is a percentage of your profit on which you do not have to pay tax. The SME profit exemption percentage in 2025 is 12.7% of the profit. Another deduction scheme that is independent of the hour criterion is the investment deduction (‘investeringsaftrek’).

Small Business Scheme (KOR) alongside employment: smart or not?

The Small Business Scheme (‘kleineondernemersregeling’ or KOR) is a VAT exemption. If your annual turnover remains below €20,000, you can choose to use the KOR. You then do not have to charge VAT to your clients and do not have to file VAT returns.

The KOR and employment can go well together, as long as you stay within the turnover limit. Are you considering the KOR? Here are the pros and cons:

Advantages:

• No need to file VAT returns: saves administrative hassle.
• You don’t have to charge VAT: this can be attractive for clients who cannot deduct VAT (private individuals, certain exempt professions).

Disadvantages:

• No VAT deduction on costs and investments: the VAT you pay yourself on business purchases cannot be reclaimed.
• You may not reverse-charge VAT: this can be a disadvantage if you do a lot of business with other VAT-liable entrepreneurs.

If your turnover remains well below €20,000 per year, the KOR can save you a lot of time. If your turnover is above that or you expect many VAT-liable costs, then the KOR is probably less interesting.

Administration for freelancers (‘zzp’ers’) alongside employment: what do you need to keep?

Even as a part-time freelancer, you must keep good administration. This includes, among other things:

• Invoices you send and receive
• Receipts for all your business expenses
• Mileage log (‘rittenregistratie’) (if applicable, for car or travel expenses)
• Hour registration (‘urenregistratie’) (especially if you want to meet the hour criterion)

Many starting part-time freelancers underestimate the administrative burden. It may seem small, but the small bits quickly pile up. Tips for keeping an overview:

• Open a business bank account: This keeps private and business finances strictly separate. This avoids a lot of searching and hassle.
• Use accounting software or an online bookkeeper: This makes keeping your administration much easier and less error-prone.

Go for it, but make sure to have your administration in order

Part-time entrepreneurship alongside employment is a great way to turn your hobby into work and earn some extra money. However, there are important points to consider in terms of tax and administration. With good support, you can avoid many worries and focus on what you love to do: entrepreneurship. A bookkeeper for zzp’ers, like Kees de Boekhouder, can help you get your zzp administration in order from day one and start without worries. Schedule a free introductory meeting with Kees de Boekhouder. We are happy to help you get started!