Time Tracking as a Freelancer: Requirements and Best Practices

Time tracking as a Dutch freelancer (zzp'er) is not legally mandatory in all cases, but it is strongly recommended - and in some situations required - to substantiate your invoices, prove the zelfstandigenaftrek, and satisfy client contracts. Understanding when and how to track your hours protects both your income and your tax position.

Is Time Tracking Required by Dutch Law?

The short answer: it depends on your situation.

Zelfstandigenaftrek (Self-Employed Deduction)

If you claim the zelfstandigenaftrek - one of the most significant tax benefits for zzp'ers - you must be able to prove that you worked at least 1,225 hours per year in your business. The Belastingdienst (Dutch tax authority) can ask for evidence during an audit. A structured time registration is the strongest proof you can provide.

The 1,225-hour requirement (urencriterium) includes:

• Billable client work
• Administration and bookkeeping
• Marketing and acquisition
• Travel time related to business
• Professional development

Without a clear time log, proving you meet this threshold during a tax audit becomes extremely difficult.

Client Contracts

Many clients - especially larger organizations and government bodies - require freelancers to submit detailed time reports. This is often a contractual obligation, not just a nice-to-have. Some clients even mandate specific time tracking tools.

VAT Administration

While the Belastingdienst doesn't require hour-by-hour logs for VAT purposes, your invoices should accurately reflect the work performed. If you bill by the hour, your time tracking is the source of truth behind those invoices. See our guide on VAT and hours for freelancers for details.

What Should You Track?

At minimum, each time entry should include:

This level of detail serves multiple purposes: invoicing accuracy, tax compliance, and your own insight into where your time goes.

Best Practices for Freelancer Time Tracking

1. Track in Real Time

The biggest mistake freelancers make is reconstructing their hours at the end of the week (or worse, the end of the month). Studies show that delayed time entry can result in 20-40% of billable hours being lost or inaccurately recorded.

Use a timer or log entries immediately after completing a task. Tools like Toggl make this easy with one-click timers and mobile apps.

2. Separate Billable and Non-Billable Hours

Not every hour you work is billable, but every hour matters for the urencriterium. Track both:

• Billable: Client work you invoice for
• Non-billable: Admin, acquisition, learning, travel

This gives you two valuable data points: your actual billable ratio and your total working hours for the zelfstandigenaftrek.

3. Use Categories or Projects

Group your time by client and project. This makes it easy to:

• Generate accurate invoices
• See which clients are most profitable
• Identify projects that consistently go over estimate

4. Write Meaningful Descriptions

"Development" or "Meeting" is too vague. Write descriptions that would make sense to your client on an invoice and to a tax inspector during an audit. For example: "API integration for order processing" or "Kickoff meeting project X with product owner."

5. Review Weekly

Set a weekly moment (Friday afternoon or Monday morning) to review your hours. Check for:

• Missing entries
• Incorrect durations
• Entries without descriptions
• Entries without a client assigned

Catching errors weekly is much easier than fixing a month of messy data.

6. Keep Records for 7 Years

The Belastingdienst can audit up to 7 years back. Your time tracking records should be stored reliably for at least that long. Digital records (CSV exports, database backups, or cloud-based tools) are perfectly acceptable.

Choosing a Time Tracking Method

Dutch freelancers typically use one of these approaches:

Spreadsheets (Excel / Google Sheets)

The most flexible option. You control the format completely, and there's no subscription cost. The downside: no timer, easy to forget, and manual effort to turn sheets into invoices.

See our guides on Google Sheets for time tracking and importing Excel time tracking data.

Dedicated Time Tracking Apps

Tools like Toggl, Clockify, and Harvest are purpose-built for tracking time. They offer timers, reporting, mobile apps, and integrations. Most have free tiers that work well for solo freelancers.

For a detailed comparison, check Toggl vs. Clockify vs. Google Sheets.

Accounting Software with Built-in Tracking

Moneybird and Simplicate include time tracking modules. The advantage: your hours and invoices live in one system. The disadvantage: the tracking experience is usually less polished than dedicated tools.

Project Management Tools

Notion and similar tools can be adapted for time tracking using databases and formulas. This works well if you already live in these tools, but requires initial setup.

The Admin Burden of Time Tracking

According to a 2023 survey by ZZP Nederland, Dutch freelancers spend an average of 5-8 hours per week on administration, with time tracking and invoicing being significant contributors.

The real cost isn't just the time spent tracking - it's the time spent moving data between systems. If you track in Toggl but invoice in Moneybird, someone has to bridge that gap. That's where the manual vs. automatic sync decision becomes important.

Synkr was built specifically for this problem: connecting your tracking tool to your Dutch accounting system so you can review and sync hours without manual re-entry. The result is less time on admin and more confidence that your records are accurate.

Common Time Tracking Mistakes

Not Tracking Non-Billable Hours

Many freelancers only track billable work. This means they can't prove their total hours for the urencriterium, and they have no insight into how much time admin, acquisition, and learning actually consume.

Inconsistent Rounding

Some freelancers round to 15-minute blocks, others to the exact minute. Pick a method and stick with it. Inconsistent rounding looks unprofessional on invoices and can raise questions during audits.

Using Multiple Systems Without Syncing

It's common to track time in one place and do accounting in another. The problem arises when these systems aren't connected - you end up maintaining two separate records of the same data, which inevitably drift apart. Read about how to cut your admin time in half for strategies to fix this.

No Backup Strategy

If your time tracking data lives only in a spreadsheet on your laptop, a hardware failure could wipe out years of records. Use cloud-based tools or ensure regular backups.

What the Belastingdienst Expects

During a tax audit related to the urencriterium, the Belastingdienst typically wants to see:

1. A structured overview of hours per week/month
2. Totals that demonstrate you meet the 1,225-hour threshold
3. Consistency between your time records and your invoices
4. Descriptions that show the work was genuinely entrepreneurial (not employment)

A well-maintained time tracking system makes this a non-issue. A shoebox of sticky notes does not.

Getting Started

If you're not tracking hours yet, start simple:

1. Choose a tool that fits your workflow (comparison here)
2. Set up clients and projects
3. Track every day for two weeks - make it a habit
4. Review and refine your process
5. Connect your tracking to your accounting system for seamless invoicing

The effort you invest in time tracking pays for itself in accurate invoices, tax compliance, and a clear picture of how you spend your most valuable resource: your time.