How to Switch to Lump-Sum Tax in 2026 - Sole Proprietor Checklist

Switching to lump-sum tax doesn't start with the tax rate -- it starts with checking whether this form makes sense for your work model and whether you're choosing it at the right time.

When to consider switching

Lump-sum wins most often when:

• You work in services and have relatively low costs
• Your PKD codes qualify for the 12% rate
• Your annual revenue is above PLN 60,000

Key deadlines

• Existing business: By 20 January of the year you want to apply lump-sum
• New business: At registration, or by the 20th day of the month following first revenue

Checklist before switching

1. Verify your PKD codes qualify (62.01.Z, 62.02.Z, 62.09.Z = 12%)
2. Calculate whether lump-sum is actually cheaper than your current form
3. Check if you need IP Box (incompatible with lump-sum)
4. Prepare revenue records template
5. Update CEIDG-1 registration

After switching

1. Start keeping revenue records (not expense ledger)
2. Calculate monthly tax advance payments from revenue
3. Track annual revenue for health insurance brackets
4. File PIT-28 (not PIT-36/PIT-36L) at year-end

Lump-sum tax calculator