Official Gazette / December 15-21, 2025

In accordance with the Law on Amendments to Tax Laws and Certain Laws and Decree-Laws, changes have been made to many regulations summarized below.

- A 1-point increase was made in Social Security Institution (SGK) premium payments, and the regular payment discount provided to employers was reduced. The SGK incentive, which was applied at 4% excluding the manufacturing sector, was reduced to 2%. The total insurance premium rate was increased from 20% to 21%, and the employer's share was raised from 11% to 12%. For this reason, since employees mostly agree on a net salary, the SGK burden on employers has increased even if they do not provide a raise. The ceiling for earnings subject to insurance premiums, which was applied as 7.5 times the minimum wage, was increased to 9 times. Thus, the premium burden for high-salary employees has risen. Employees who have agreed on a gross salary will receive a lower net wage in the new year if they do not receive a raise.

- The practice of deducting mortgage interest from rental income for taxation purposes for homes purchased with a loan and rented out has been abolished. Mortgage interest can no longer be shown as an expense. This change does not cover workplaces.

- The regulation for a tax loss penalty, which was 25% of the tax that should be paid for those who do not correctly declare the sale price in title deed transactions, has been changed to 100%. In other words, those who show the title deed sale value as less than it is will face an extra tax penalty equal to the entire amount of tax they should have paid.

- A new tax of 0.2% (two per thousand) of the vehicle sale price has been introduced for vehicle sales made at notaries.

- The 2026 real estate tax value has been capped at a maximum of 2 times the 2025 tax. Increases to be made until 2030, when real estate taxes will be re-evaluated according to market rates, will be limited to the revaluation rate. (Previously, the regulation was limited to half the revaluation rate.)

- Tuition fees for foundation universities, excluding preparatory and 1st-year classes, cannot exceed the average of the CPI/PPI.

- The fourth provisional tax period application, which was abolished in 2022, has started again. Accordingly, taxpayers will also need to file a declaration for the months of October-November-December 2025 and pay provisional income tax for the October-December 2025 period in February 2026.

- A fee that must be paid once a year, in addition to income tax, has been introduced for businesses such as dentists, veterinarians, jewelers, real estate agents, car dealers, and medical centers. The fee to be paid in metropolitan cities will be applied as twice that of other cities.

- The Bağkur support applied for young entrepreneurs has been abolished. For those under 29 years of age who establish a sole proprietorship for the first time, Bağkur premium payments were made by the treasury for the first 12 months. As of 2026, this practice is being abolished. It may be logical for those who are thinking of opening a sole proprietorship and have not owned a company before to submit their establishment application before the new year, before the new legislation enters into force.

- The premium rate valid for military service and overseas debt borrowing will be increased from 32% to 45% as of 2026. Therefore, it will become 1.5 times more expensive.

- The President has been granted the authority to determine the state contribution in the Private Pension System (BES), which is currently applied at 30%, from 0% to 50%.

The Central Bank of the Republic of Turkey (TCMB) cut interest rates again after September 2025, lowering the advance interest rate from 42.25% to 39.75% and the rediscount interest rate from 41.25% to 38.75%.