A month's calendar: what is due on which day?

Nuri Usta the baker's rush around the 25th

Nuri Usta's bakery is the oldest in the neighbourhood. The dough is kneaded at the same time every morning; nobody sets an alarm for it, the routine is settled. Tax days are not like that. Every month around the 25th the phone rings and the mali müşavir (accountant) asks: "Muhtasar tomorrow, VAT on Thursday, and SGK at the end of the month. Is the money ready?" And every month Nuri Usta asks the same thing: "When was which one this month?"

Yet the calendar is almost the same every month. Only the weekends and the religious holidays change. In this lesson we put a month's tax and premium days in order, then look at a routine you set up once and use the same way every month.

We explained what each tax is in the article Tax calendar (in Turkish). Here we go one step further: which day of the month you do what.

The rule: this month's business is reported next month

Almost everything is done for the previous month. The VAT on the invoices you issued in September and the premium of the employee who worked in September are reported and paid in October. So the October calendar is really "September's accounts".

The fixed days of the month

Let's go into a bit more detail.

Withholding and premium service return (muhtasar ve prim hizmet beyannamesi; accountants call it MUHSGK for short). On a single form it reports the employee's days, earnings and the tax withheld from their wage to both the tax office and SGK. The last day is the 26th of the following month. The income tax and stamp duty withheld from wages are also paid on the same day. If you rent your shop from a person rather than a company, you withhold part of the rent as tax yourself and pay it in (rent withholding, kira stopajı); that also goes with this return. Under simplified taxation you do not withhold tax on rent. If you have no employees and no withholding, this line does not concern you. If you have no employees but do have withholding, small businesses that meet the conditions can also file this return once every three months (on the 26th of January, April, July and October); ask your mali müşavir which one applies to you.

SGK premium. The return goes on the 26th, but the premium is paid later: according to SGK, by the end of the following month. So there are a few days between filing and payment.

VAT. The 28th of the following month, both the return and the payment. This day applies under a determination GİB made at the end of 2022; it may change in the future.

Bağ-Kur. Your own premium. The last day of the following month. No return is filed for it; the debt arises on its own, and remembering to pay is your job. Who pays it and the 2026 amounts are in the lesson SGK and Bağ-Kur registration.

Provisional tax. Not every month, but once every three months: the 17th of the second month after the period. For the July–September 2026 period the last day is 17 November 2026. Not under simplified taxation.

Stamp duty. If you have employees, the stamp duty on the payroll goes with the muhtasar. Other papers may need a separate return; that is also generally by the 26th. Your mali müşavir knows which ones fall to you.

If the last day falls on a holiday

In tax the rule is this: if the last day of a period falls on an official holiday, the period ends on the first working day after the holiday (Tax Procedure Law art. 18). In practice Saturday and Sunday count the same way; because 28 November 2026 is a Saturday in the GİB calendar, October VAT moves to 30 November. SGK opens the same path for the SGK premium: if the last day falls on a holiday or a weekend, payment can be made on the first working day after it.

Religious holidays can also bring extra extensions. In May 2026, when Kurban Bayramı fell, the April period muhtasar (together with stamp duty) was extended to 3 June and its VAT to 5 June (GİB circular VUK-199/2026-5 dated 15 May 2026). An extension does not always come; when it does, GİB announces it.

The next two months (2026)

28 October is the eve of Republic Day; its afternoon is an official holiday. Don't leave it to the last day; pay the VAT a day or two early. Confirm Bağ-Kur's last day in these months on the debt screen in e-Devlet. Before paying, check the days once more in GİB's tax calendar; if anything changes, it shows there.

Set up the calendar once, the same every month

Like the dough in the bakery: the routine is set up once, then it runs by itself.

1. Set recurring reminders on your phone. The 20th of every month: "Ask the mali müşavir for the amounts." The 24th: muhtasar. The 26th: VAT. Two days before the last working day of the month: SGK and Bağ-Kur. If you set the reminder before the last day, you don't have to deal with holiday shifts.
2. Agree a fixed amounts day with your mali müşavir. For example, the 20th of every month. On that day you should have the amounts to be paid. The tax assessment slip (tahakkuk fişi), the paper showing the amount to pay and the last day, is created when the return is filed; have your mali müşavir send it to you once the return is filed.
3. Delete the lines that don't apply to you. Under simplified taxation, remove VAT and provisional tax. If you have no employees and no payment you withhold tax from, remove the muhtasar and SGK lines. If you are a company, ask your mali müşavir about your own Bağ-Kur status.
4. Don't leave payment to the last day. On the last day the bank is busy, the internet goes down, the limit is reached. Paying a day early costs nothing.

Here is how Nuri Usta's September accounts went: his mali müşavir wrote him the amounts on 20 October, filed the returns on 22 October and sent the tax assessment slips. Muhtasar 6,000 lira, VAT 9,000 lira, SGK 18,000 lira. Nuri Usta paid the muhtasar on 23 October, the VAT on 27 October and SGK on 30 October. For Bağ-Kur he had given his bank a standing payment order. This time the phone did not ring on the 25th.