Common Errors and Systemic Issues in Tax Audits in Türkiye

In 2025, Türkiye’s tax audit system reached a new stage in combating the informal economy by identifying a tax base discrepancy worth 748 billion Turkish lira. While these figures mark an impressive achievement, they also expose underlying structural problems within the tax system and taxpayer compliance practices.

Institutionalized Tax Base Concealment Practices

Large and medium-sized enterprises account for around 90% of the total tax base discrepancies, reflecting a structured and institutionalized form of tax evasion. The audits conducted in this segment revealed a 469 billion lira discrepancy — a result of audit efforts focused on high-turnover, low-tax enterprises rather than small businesses.

The detected errors were particularly concentrated in the following areas:

• General audit subjects excluding false document use (325.3 billion lira): these cases typically involved taxes that were “easily collectible” but deliberately hidden through structured deficiencies in accounting records
• Mismatch between income and expenses: a monitoring and compliance program launched in 2025 reached 135,000 taxpayers, resulting in a tax base increase of 136.8 billion lira
• Documentation deficiencies: approximately 75% of audited taxpayers underwent an inspection for the first time in the past five years, reflecting poor record-keeping discipline

Structural Imbalances Within the Tax System

For international investors, one of the most critical risks to consider is Türkiye’s heavy reliance on indirect taxes. According to data confirmed by the Ministry of Treasury and Finance and Minister Mehmet Şimşek:

• The share of indirect taxes in total tax revenues stands at 61.9% (down from 65.5% in 2024)
• The direct tax rate is 13.5%, below the OECD average
• This imbalance imposes a disproportionate burden on wage earners and low-income groups

Consequently, the tendency of taxpayers to make errors largely stems from systemic incentives. Maintaining low direct tax rates encourages businesses to pursue tax minimization strategies, thereby complicating audit processes and increasing administrative burdens.

Lack of Voluntary Compliance and the “Invitation to Explain” Mechanism

One of the most significant findings of 2025 was that taxpayer compliance can be effectively achieved through guidance and advisory mechanisms. The number of taxpayers invited to provide explanations tripled from 2024 to 2025, reaching 51,356, leading to an additional 86.8 billion lira of tax base detection. This result indicates that in most cases, errors are corrected when clear instructions and communication channels are provided.

These outcomes suggest that most taxpayer errors stem not from deliberate evasion, but from procedural and record-keeping deficiencies. The audit rate increased from 2.91% in 2024 to 6.72% in 2025, showing that strengthened audit capacity is yielding more findings.

Strategic Insights for Entrepreneurs

For international entrepreneurs operating in Türkiye, effective risk management in tax compliance should focus on the following areas:

• Accounting documentation: maintaining comprehensive and systematic records to prepare for potential tax audits
• Consistency between income and expenditures: ensuring all expenses are clearly linked and justified within the scope of business activities
• Proactive compliance: benefiting from advisory and guidance services offered by the Revenue Administration (Gelir İdaresi Başkanlığı) to minimize tax risks

At a systemic level, Türkiye’s efforts to compensate for revenue shortfalls through indirect taxation and anti-informal economy measures, rather than increasing direct taxes, continue to expand the compliance obligations of businesses. For foreign investors and entrepreneurs, understanding this structural tax reality is key to building resilient and transparent business operations in the country.