Corporate Tax Deadlines in Turkey: Annual and Advance Tax Calendar

Corporate tax compliance in Turkey does not consist of a single annual filing. Companies generally calculate and pay advance corporate tax during the accounting period and then reconcile those payments in the annual corporate tax return.

The calendar is especially important for foreign-owned Turkish companies because group reporting deadlines, intercompany reconciliations and headquarters approval processes may not align with Turkish statutory dates. Accounting records therefore need to be closed well before the final filing day.

Turkey Corporate Tax Calendar for 2026

The following dates apply to a company whose accounting period is the calendar year. The table reflects the Revenue Administration calendar available as of 20 August 2026.

*The 2027 dates should be confirmed against the GİB tax calendar and any Revenue Administration circular issued closer to the deadline.

When Is the Annual Corporate Tax Return Due?

A corporate tax return must generally be filed from the first day through 23:59 on the last day of the fourth month following the month in which the accounting period closes.

Accordingly, a company using the standard 1 January–31 December accounting period filed its return for the 2025 financial year between 1 and 30 April 2026. The assessed corporate tax was also payable by 30 April 2026.

The return is submitted electronically. Filing a return and paying the amount assessed are related but distinct compliance steps. A successful electronic submission does not by itself prove that the corresponding payment was completed.

What Is Advance Corporate Tax?

Advance corporate tax, also called provisional or temporary corporate tax, is paid during the current accounting period and credited against the corporate tax calculated in the annual return.

The calculation is cumulative. For example, the second period is based on results for the first six months, not only the transactions recorded during April, May and June. Advance tax already calculated for the earlier period is taken into account when determining the amount payable.

1. The first return covers the first three months.
2. The second return covers the first six months.
3. The third return covers the first nine months.
4. The fourth return covers the full twelve-month period.
5. Eligible advance tax payments are credited in the annual corporate tax return.

Companies can use our live Temporary Tax Calculator for an indicative calculation. The final return must still be prepared from the company’s complete accounting records and applicable tax rules.

The Fourth Advance Tax Period Has Returned

Older Turkish tax calendars may show only three advance tax periods. That information is no longer sufficient for current compliance.

Law No. 7566, published in the Official Gazette on 19 December 2025, removed the wording that limited advance taxation to the first nine months of the accounting period. As a result, the fourth advance tax period applies again.

The official 2026 calendar confirms that the October–December 2025 fourth-period corporate advance tax return and payment were due on 17 February 2026. Companies should therefore ensure that their 2026 compliance calendars also include a fourth-period filing in February 2027, subject to the official 2027 calendar and any later circular.

How Advance Tax Is Reconciled in the Annual Return

The annual return determines corporate tax for the completed accounting period. Advance corporate tax paid during that period is then credited against the annual liability, subject to the applicable rules and matching tax-office records.

Only amounts that can be matched and credited under the tax records should be treated as available advance tax. The accounting balance, filed returns, accrual slips and payment records should be reconciled before the annual declaration is approved.

What About Companies With a Special Accounting Period?

A company authorised to use a special accounting period does not automatically follow the April annual return deadline. Its return is generally due by the end of the fourth month following the month in which its special accounting period closes.

For example, if an authorised special accounting period closes on 30 June, the general annual filing deadline falls at the end of October. The corporate tax assessed through that return is payable by the end of the filing month.

Advance tax periods must also be mapped to the company’s approved accounting period. Foreign groups should not simply import the parent company’s fiscal calendar into Turkish compliance software without checking the accounting period registered with the Turkish tax office.

Do New or Inactive Companies Still Have to File?

A newly registered company may have a short first accounting period. Its annual return generally covers the period between its tax registration and the end of its applicable accounting period.

A company should not assume that a return is unnecessary merely because it recorded a loss, generated no revenue or remained commercially inactive. The corporate taxpayer status and current tax-office registration determine the filing obligation. Dormant companies may still have accounting, return and notification requirements until they are formally liquidated and deregistered.

Information Needed Before the Annual Filing

The annual corporate tax process normally requires more than a profit figure. Depending on the company’s activities, the return and its supporting work may include:

• a detailed balance sheet and income statement;
• taxable-profit reconciliations and non-deductible expenses;
• loss carry-forward information;
• tax exemptions, deductions and incentives;
• taxes paid through withholding or in foreign jurisdictions;
• advance corporate tax accrual and payment records;
• beneficial-owner information;
• information concerning foreign shareholders where applicable;
• related-party transactions and required transfer-pricing information;
• minimum corporate tax calculations where applicable.

Companies with related-party transactions should coordinate the annual return with their transfer-pricing review. Our guide to Transfer Pricing in Turkey explains the principal related-party transaction rules.

Weekend, Public Holiday and Extension Rules

When the final day of a statutory period falls on an official holiday, the period generally continues until the end of the following working day. The 18 May 2026 first-period advance tax deadline is a practical example.

The Revenue Administration may also extend a deadline by circular. An extension should only be relied upon after an official announcement has been issued. A professional newsletter, social-media post or draft announcement is not a substitute for the applicable GİB circular.

Corporate Tax Deadline Checklist

Common Calendar Mistakes

• using an old calendar that contains only three advance tax periods;
• treating advance tax periods as independent quarters instead of cumulative calculations;
• assuming every company has a 31 December year-end;
• waiting for headquarters approval until the statutory deadline;
• confusing electronic submission with successful payment;
• crediting advance tax that cannot be matched to tax-office records;
• assuming a public holiday or administrative extension without checking GİB;
• overlooking return obligations because the company had no activity or recorded a loss.

Planning for Foreign-Owned Turkish Companies

Foreign-owned companies should build internal closing dates around the Turkish filing calendar. Related-party invoices, management fees, foreign-exchange balances, financing costs, withholding taxes and foreign tax documents often require additional review before the corporate tax calculation can be finalised.

Our Tax, Bookkeeping and Accounting Services in Turkey cover statutory bookkeeping, periodic tax returns, year-end reconciliations and annual corporate tax compliance. Technical questions concerning exemptions, deductions or cross-border transactions can also be reviewed under our Turkish Tax Advisory Services.

Official Sources

• Turkish Revenue Administration: Official Tax Calendar
• Turkish Revenue Administration: Corporate Tax Filing and Payment
• GİB: 2026 Corporate Tax Filing Guide Announcement
• GİB: 30 April 2026 Annual Corporate Tax Deadline
• GİB Legislation Database: Law No. 7566
• Digital Tax Office

This article provides general information as of 20 August 2026. Filing dates may be affected by special accounting periods, public holidays or official extensions. The current GİB calendar and applicable circulars should be checked before filing or payment.