What to put in your sole trader costs – a 50-item checklist for 2026

Tax-deductible costs are a legal way to reduce the tax base. Every zloty spent for the needs of the business, documented and linked to revenue, means less tax to pay. In a sole trader business taxed on the scale or the flat tax, every PLN 1,000 of cost means PLN 190 less PIT (flat tax) or PLN 120 to 320 less (scale, depending on the bracket). For the lump-sum tax, costs do not matter – the rate is applied to revenue.

The general rule from Article 22(1) of the PIT Act: a cost is an expense incurred in order to earn revenue or to preserve or secure its source, with the exceptions listed in Article 23. Below is a checklist of 50 of the most common costs.

Office infrastructure costs (1–10)

1. An office – rent, utilities, cleaning, technical services
2. A flat used as an office – proportionate running costs (rent, utilities) for the part of the flat used in the business; since 2023 residential premises and buildings are not depreciated for tax purposes (Article 22c point 2 of the PIT Act), including those entered in the register before 2022 – details in the article A flat in business costs
3. Coworking – the full amount of the subscription
4. Buying office furniture – up to PLN 10,000 one-off into costs, above that depreciation
5. Computer equipment – a laptop, a monitor, a printer, an external drive
6. Software – licences, SaaS subscriptions (Microsoft 365, Google Workspace, Adobe, IDEs)
7. A mobile phone – buying the device, the subscription, roaming
8. Internet – a subscription at the office or a proportionate part at home
9. IT services – hosting, domain, backups, VPN, firewall
10. Office supplies – paper, toner, pens, staplers

Transport costs (11–16)

11. Car leasing – instalments, initial fees (up to the car value limit of PLN 100,000 / 150,000 / 225,000) – details in the article A car in the company 2026
12. Fuel – for a company car (100% or 75% depending on the VAT mode)
13. Third-party liability / comprehensive insurance (OC/AC) – proportionate to the car value limit (PLN 100,000 / 150,000 / 225,000)
14. Servicing and repairs – the workshop, spare parts, changing tyres
15. Parking and motorways – on business trips
16. A private car used in the business, not entered in the fixed assets register – the cost is 20% of the expenses (Article 23(1) point 46a of the PIT Act); the “mileage log” as a cost in PIT has not existed since 2019

Outside services costs (17–22)

17. An accounting firm – invoices for bookkeeping services
18. Legal services – advice, conducting disputes, contract audits
19. Tax advice – interpretations, reliefs, optimisation
20. Marketing and advertising – campaigns, SEO, copywriting, graphics, videos
21. Translations and proofreading
22. Courier services and shipping orders to customers

Staff costs (23–30)

23. Pay under employment contracts (gross)
24. Pay under contracts of mandate and contracts for specific work
25. B2B contracts with subcontractors (invoices)
26. The employer’s ZUS (Polish social insurance) contributions (pension, disability, the Labour Fund, the Guaranteed Employee Benefits Fund, accident)
27. Benefits – a sports card (Multisport), medical care, subsidised lunches
28. Medical examinations of employees (initial, periodic)
29. Health and safety training
30. Protective clothing and personal protective equipment

Education and development costs (31–36)

31. Industry training for the owner and employees
32. Online courses (Udemy, Coursera, Pluralsight)
33. Professional certifications (PMP, AWS, Google, Cisco)
34. Professional books and e-books
35. Subscriptions to industry magazines and portals
36. Conferences and trade fairs – the participation fee, flights, hotel

Entertainment and meeting costs (37–40)

37. Lunches with customers – documented with a business purpose
38. Coffee and catering in the office – for customers and employees
39. Company gifts for suppliers and customers (up to PLN 200) – with the company’s logo on the product
40. Business trips – hotel, transport, per diems (domestic per diems of PLN 45 a day in 2026)

Financial costs (41–44)

41. Bank fees – running the account, transfers, company cards
42. Interest on a business loan and on finance leasing
43. Premiums for the company’s property insurance (business third-party liability, equipment, buildings)
44. Notarial and court fees for business matters

Public-law costs (45–48)

45. The entrepreneur’s ZUS contributions (pension, disability, sickness, accident) – deductible from income or as a tax-deductible cost
46. The Labour Fund and the Solidarity Fund – only as a tax-deductible cost
47. The health insurance contribution – partly, depending on the form of taxation (details in the article Health insurance contribution 2026)
48. Membership fees in chambers of commerce and industry associations

Specific costs (49–50)

49. Group insurance for employees (health, life)
50. Donations for public benefit purposes (up to 6% of income, not counted as tax-deductible costs, but deducted from income)

What is not a cost – the red list

Article 23 of the PIT Act lists the exclusions precisely:

• Fines, tickets, penalties – even for business breaches
• Health insurance contributions under the tax scale (entirely excluded since 2022)
• Entertainment costs (lavish receptions, luxury gifts above PLN 200)
• Interest on tax arrears
• Personal insurance of the owner (life, private accident insurance)
• A loss on the sale of a private property entered in the fixed assets register
• Expenses on fixed assets above PLN 10,000 in one go (depreciation only)

Documentation – the key to defending a cost

Every cost must be documented. In practice this means:

1. A VAT invoice or a receipt with the company’s NIP (tax identification number) – for VAT an invoice is required
2. Proof of payment (a bank statement, a confirmation of a transfer)
3. Documentation justifying the link with the business – for example, a note in the calendar for a lunch with a customer, a list of training participants, photos from a trade fair
4. Keeping it for 5 years from the end of the year in which the deadline for paying the tax expired

B2B invoices are issued in KSeF (the national e-invoicing system) – from 1 February 2026 for the largest taxpayers, from 1 April 2026 for the others – and are available in the Ministry of Finance’s system, but the retention of accounting evidence is governed by the deadlines in the Accounting Act (Article 74) and the Tax Ordinance Act. The details are in the article KSeF 2.0 – company obligations in 2026.

Summary

Good bookkeeping is not only careful booking – it is also proactively looking for costs. See our KPiR (revenue and expense ledger) service for sole traders. We are an accounting firm, not a tax adviser: we keep the books, prepare returns and explain how the rules translate into your settlements. Tax advice and opinions, and representation in proceedings, are provided within the scope allowed by the Tax Advisory Act. Contact us through the home page or by phone.

Sources: podatki.gov.pl – tax-deductible costs, the PIT Act (Articles 22, 22c and 23).