Sole Proprietorship in Turkey: 2026 Setup Guide

For entrepreneurs who want to open a sole proprietorship in Turkey, the first question is not “how do I go to the tax office?” but “which door should I enter through?” Tax registration alone is not enough; depending on the nature of the activity, a tradesman chamber, tradesman registry, trade registry, MERSİS, municipality and SGK layer may also apply.

For real persons, the commencement-of-activity notice is filed within 10 days from the start date under VUK art. 168. The notice is given by the taxpayer, a lawyer or a professional within the scope of Law No. 3568. Channel: in person, by post or via the Digital Tax Office. If it is not filed on time, a first-degree procedural penalty arises. Tax status does not start on the notice date; it starts with actual commencement and the tax office’s establishment/yoklama process.

This guide is written against a source check of 1 September 2026. Istanbul chamber, registry and SMMM workload amounts are not a single Turkey-wide rule. Not every digital service or consultancy is automatically a self-employed profession (serbest meslek); the split turns on personal labour, scientific/professional knowledge and commercial organisation.

1️⃣Choosing the Right Status

Before setting up a sole proprietorship, clarify the nature and scale of the activity, stock/shop needs, trade name and bookkeeping regime. “Şahıs işletmesi / şahıs şirketi” is everyday language; it is not a separate capital-company form established under the TTK the way Ltd./A.Ş. are. The English term “sole proprietorship” is a practical label for Turkey’s real-person tax and registry statuses; it is not a foreign legal form equated one-to-one. Distinct statuses are the real-person merchant (tacir), tradesman and craftsman (esnaf ve sanatkâr), self-employed professional (serbest meslek) and income-tax-exempt tradesman. Keeping books on the balance-sheet basis does not by itself create a trade-registry duty.

The table below is a starting point for small ventures in Istanbul; occupation, a Coordination Board decision and local chamber practice can change the outcome:

Status matching by activity type

Short checklist for NACE selection

The main NACE code must reflect the actual activity that generates income. A wrong NACE can lead to the wrong chamber registration, the wrong licence class, the wrong bookkeeping regime and sometimes the wrong document type. In İTO applications, the NACE in MERSİS and the NACE on the papers are specifically required to match.

• •What is my main income item?
• •Do I have a secondary income item?
• •What do I deliver to the customer?
• •Is the activity continuous or project-based?
• •Do I hold stock?
• •Is there a physical shop or workshop?
• •Will there be employees?
• •Is there a special activity that requires a chamber/registry or sector licence?

Software, design or consultancy is assessed as a self-employed profession if personal labour and professional knowledge dominate, and on the commercial-income side if stock/organisation and the character of a commercial enterprise dominate. For barber or grocer activity, the tradesman door is tested as a rule in Istanbul; there is no absolute ban that it “cannot be entered in the trade registry anywhere”. If you buy and sell goods, hold stock and use a trade name, the real-person merchant route comes into play.

2️⃣Step-by-Step Setup Procedure

The backbone of setup is tax registration. In Istanbul the practical order in most files is as follows:

In short: tax registration can be started in 1 day in most files; a fully compliant activity start varies by scenario from 1 day to several weeks.

3️⃣Required Documents and Systems

The list below groups documents often needed in 2026 Istanbul practice; it is not a “definitely required in every file” logic. Current conditions must be confirmed with the relevant institution.

Core file for tax registration

• •Commencement/Cessation of Activity Notice
• •Identity details
• •Address basis (at yoklama / in a special case)
• •Power of attorney (if someone else will act)
• •Electronic Service Request Notice (for real persons)

Typical file for tradesman registry and chamber

• •Copy of identity document
• •Copy of vehicle licence in some lines of work
• •Exemption certificate for those exempt from tax
• •Residence certificate
• •Personal application or power of attorney

Typical file for trade registry and İTO

• •MERSİS application and request number
• •Petition (name, capital, opening date, activity, NACE)
• •Chamber registration declaration
• •Signature declaration or new identity + MERSİS authority acceptance
• •Copy of tax plaque
• •Foreign-national documents if required

In real-person commercial-enterprise applications, İTO may ask that working capital of at least 100 TL be shown. This is Istanbul practice. Book information may be requested in the petition; a balance-sheet book is not by itself a national registration condition.

Notary, e-signature, e-documents and bookkeeping regime

An e-signature is not mandatory at every opening; it eases e-document and digital processes. The SMMM setup fee is shown separately in the cost section below as an Istanbul workload reference.

• •A self-employed professional issues a professional receipt for professional collections and moves to e-SMM by the end of the third month following the month of commencement.
• •In commercial activities, the invoice, e-Fatura and e-Arşiv Invoice regime is assessed separately.
• •From 1 January 2026 the monetary threshold for issuing e-Arşiv Invoices has been removed for “other taxpayers”.
• •For those on the simplified lump-sum method and the operating-account basis, the 3,000 TL threshold including taxes continues until 31 December 2026; application without an amount limit starts for them on 1 January 2027. The general e-Fatura transition threshold and sector-specific duties are assessed separately.

4️⃣2026 Setup and First-Year Costs

There is no single national “sole-proprietorship setup cost”. The SMMM amounts below are read from İSMMMO’s 2026 recommended workload-based tariff (Istanbul; monthly and VAT included). This tariff is not the Official Gazette TÜRMOB minimum fee tariff and is not the firm market price charged to the client. İSTESOB duty/dues amounts are not written because they could not be verified on the union’s page in this review.

İSMMMO amounts are recommended workload. Volume of work, document count, employees, e-transformation, extra advice, rent, licence, ÖKC, POS and sector permits are priced separately. Local chamber fees must be confirmed with the relevant chamber.

2026 official and tariff references

Start-up cost by setup scenario

The amounts below show only the core steps at the setup stage; monthly and periodic operating expenses are kept outside the totals.

Expenses not included in the setup total

The following expenses are not included in the amounts above:

• •Monthly certified-public-accountant service
• •Bağ-Kur premium
• •Income tax, VAT and return stamp taxes
• •Workplace rent and deposit
• •Municipal workplace opening and operating licence
• •E-signature and private integrator services
• •Stamp/seal
• •Cash register and POS device
• •Trademark registration
• •Master-craftsman certificate and sector permits
• •Employees’ wage and SGK costs

Result: as of 1 September 2026 the sole-proprietorship setup cost is not fixed. Tax registration alone and the İSMMMO recommended setup fee can start from 2,240 TL. If tradesman registration is required, İSTESOB items are confirmed with the union. On the trade-registry route the İTO establishment fee, certificate, TTSG announcement and any separate announcement expense are added; these are not a single registration-and-announcement item. The notary/signature step is separate.

The setup fee and the business’s first-year cash need are not the same. Monthly SMMM, 4/b, tax, rent, licence and employee costs must be budgeted separately at the start of activity.

5️⃣4/b Bağ-Kur Duties

A real person who sets up a sole proprietorship is as a rule treated as insured under article 4/1-b of Law No. 5510. This includes those who are income-tax taxpayers because of commercial or professional income and those who are exempt from income tax and registered in the tradesman and craftsman registry.

The start of 4/b insurance, for income-tax taxpayers, is the date tax status starts (5510 art. 7). Tax offices and the tradesman registry notify the Institution (art. 8); if no notice has been given, the person may apply with documents.

If 4/a and 4/b overlap in the same month

The following rule is read from the TÜRMOB archive copy of SGK Circular No. 2025/7 (Presidency of the Social Security Institution of the Republic of Turkey, General Directorate of Pension Services, 19.02.2025, ref. E-58680964-201.02.01-112409200; no separate circular page was found on sgk.gov.tr). The circular amends heading “5- Overlap of service periods where part-time work is less than 30 days” of Insurance Transactions Circular No. 2013/11. From January 2025, if 4/a days in the month are below 30 and a 4/b status exists in the same month, only 4/b for the overlapping period is cancelled, regardless of the missing-day reason; the remaining days are completed to 30 as 4/b. 4/a days at more than one workplace are added together; if the total is 30, no 4/b premium is charged for that month. The month is treated as 30 days. If there is an entry or exit, a day-by-day count is made. If there is no entry or exit, in a partial month 4/a starts on the first day of the month and 4/b starts on the day following the end of 4/a. Incomplete months up to 31.12.2024 are not completed automatically; a written request is required for March 2011–December 2024.

2026 premium structure (SGK PEK × 5510 rates)

For the 5-point reduction (5510 art. 81/j), premiums must be paid within the legal period and the person must have no own 4/b debt (or the restructuring must be operating). Article 88 of Law No. 5510 says the 4/b premium is paid by the day the Institution will determine in the month following the month the premium relates to. In SGK’s 2026 official statement, that day is the last day of the month following the month the premium relates to. The current legal period must be checked on e-Devlet or the SGK debt screen.

Registration, follow-up and payment process

• •Tax commencement-of-activity notice (10 days)
• •4/b registration by Institution notice or by direct application
• •e-Devlet: 4B Registration Record, Debt Status, Payment Statement, Daily Earnings Declaration
• •Payment of the 4/b premium, according to the SGK statement, by the last day of the month following the month the premium relates to; check the due date on the e-Devlet/SGK debt screen
• •If there is a worker: 4/a workplace declaration + employment entry + e-Bildirge/MUHPHB
• •For healthcare: 30 days of premium + no more than 60 days of debt on the application date

Calculation examples

Scenario 1 — No employee, no 4/a work elsewhere: if declared at the floor, the monthly premium is 11,808.23 TL; 10,156.73 TL if the 5-point reduction conditions are met.

Employee-cost example — On the 33,030 TL gross minimum wage the employee share of 15% = 4,954.50 TL and is withheld from gross pay. The unreduced employer share of 23.75% = 7,844.63 TL. Reading the full 38.75% as an extra employer expense on top of gross pay is therefore wrong; the unreduced employer cost is 33,030 + 7,844.63 = 40,874.63 TL.

Circular Example 1 — A person who, while 4/b, starts 4/a on 8/1/2025 and is reported for 10 days of 4/a in January: 1–7 January 7 days 4/b, 8–17 January 10 days 4/a, 18–31 January 14 days 4/b. In the monthly linking, the month is 30 days.

6️⃣Timeline and Checklists

Tax registration can be started in 1 day in most files. Because of yoklama, a registry appointment, municipal papers, e-Tebligat and employee registration, it is not correct to say “everything finishes in a single day”.

A fully compliant activity start varies by scenario from 1 day to several weeks.

Scenario A — Home-office / digital-service checklist

• •Is the activity commercial or a self-employed profession, and has the matching document type been set correctly?
• •For a home office, is there a rent/title and apartment/management-plan obstacle?
• •From the municipality’s side, does customer traffic or a signboard arise?
• •Have e-Tebligat and the bookkeeping regime been planned?
• •If there are foreign customers, how will VAT and the collection flow be tracked?

Scenario B — Tradesman checklist

• •Have tax registration + chamber + tradesman registry been planned together?
• •Is there a municipal operating licence and, if required, a master-craftsman certificate?
• •If food/cosmetics, has any extra permit/inspection need been checked?
• •Is the document regime and ÖKC plan ready for cash-retail sales?
• •İSTESOB duty and dues do not cover municipal/equipment costs; the amount will be confirmed with the union

Scenario C — Real-person merchant checklist

• •Are MERSİS + trade registry + trade name ready?
• •Have the balance-sheet basis and the e-Defter/e-Belge architecture been planned?
• •Are the chamber registration declaration and petition fields complete?
• •Is the İTO appointment and physical-application document set complete?
• •Has the “I will just open tax and look later” approach been left behind?

7️⃣Common Mistakes

❓Frequently Asked Questions

9️⃣Tax Types and Filing Duties

The earnings of a sole proprietorship are subject to the owner’s income tax. The tax base is not turnover; it is net commercial or professional profit determined under tax law. It is not corporate tax. VAT, provisional tax, withholding, MUHPHB and stamp tax arise by transaction.

Filing periods, VAT/withholding status and special exemptions change with the activity structure. The tax calendar must be put in writing with an SMMM when the tax status is opened.

Young-entrepreneur earnings exemption

Real persons who have not reached age 29 on the commencement date and who meet the other conditions of GVK repeated article 20 may, in 2026, exempt from income tax the part of qualifying commercial, agricultural or professional earnings up to 400,000 TL for three tax periods including the start calendar year. The amount is not turnover or a cash grant. It does not apply automatically to Ltd./A.Ş. corporate earnings.

The 4/b premium support in 5510 art. 81/1-k was abolished from 1 January 2026 by Law No. 7566. The income-tax earnings exemption is a separate rule and continues. See the young-entrepreneur guide for detail.

Young Entrepreneur Tax Exemption in Turkey (2026)

🔟Home Office, Rent Withholding and Expenses

Using a home address as a workplace must be assessed together for tax, the lease, condominium/management plan and municipal licence. There is no guaranteed licence outcome.

Rent and withholding

If the property belongs to the business owner, no rent to oneself and no GVK 94 withholding arise; expense is examined under the business-related share and depreciation rules. If the workplace or home office is rented from a real person, an actual-basis taxpayer obliged to withhold as a rule withholds 20% on the gross rent (GVK 94). A net contract is grossed up.

The result changes if the lessor is a legal person or a special exemption applies. Renting from a spouse or relative is not automatically withholding-free; comparable rent and documentation can arise. The lessor’s tax status must be checked before the contract.

Main items that can be written as expenses

• •General expenses directly related to obtaining and maintaining the earnings
• •In a self-employed profession, if part of the residence is a workplace, writing the documented business-related rent as an expense under the statutory conditions; rent expense is not written on an owner-occupied home
• •In a self-employed profession, half of home-office heating, lighting and water-type expenses
• •If the workplace belongs to the owner, depreciation under its conditions or half of home-office depreciation
• •Depreciation of fixtures used in the professional/commercial activity
• •Travel, communication, software and professional-publication expenses related to the activity
• •Statutory rate and monetary limits on passenger-car expenses and leases

Not every outlay is an expense. Document, nexus with the activity and the statutory limit are examined separately. A VAT deduction is not the same thing as an income-tax expense. There are special rate/amount limits on passenger cars and mixed use. Undocumented or wholly personal expenses cannot be deducted.

1️⃣1️⃣Sole-Proprietorship Closure Steps

Completely stopping taxable transactions is cessation of business. Real persons must notify cessation within one month from the event date.

Closing the tax file does not automatically close the chamber, registry, municipal licence, 4/b, 4/a employer file, e-documents/ÖKC and final returns. The layers close separately.

1️⃣2️⃣Sole Proprietorship or Limited Company?

The choice must not be made on setup cost alone. Personal liability, profit level, partnership and investment plan, public debts and the closure process must be assessed together.

In low-risk, one-person starts a sole proprietorship can be practical. Where contract risk is high, there is a partner/investor plan or a corporate structure is needed, a limited company may be more suitable; the decision should be made with concrete figures.

✅Practical Takeaways

Setting up a sole proprietorship is not just filling one form. The right status, NACE, tax and e-document regime, 4/a–4/b day count, real cost, home-office withholding and the closure plan must be managed together.

As of 1 September 2026 the practical priority order is as follows:

• •Activity + address + NACE + status choice
• •Commencement-of-activity notice within 10 days
• •e-Tebligat and books/document regime
• •Solving the tradesman or trade-registry need through the right door
• •Budgeting the 4/b premium and any employee processes

In a correctly planned file both opening and first-year cost become more predictable; the wrong door and wrong assumptions cost both time and money.