Legal Certainty Post-Audit: A Comprehensive Analysis of Tax Assessment Letters (SKP) in the Modern Tax Regime

In the cycle of tax law enforcement, a Tax Audit is a vital instrument to test Taxpayer compliance. However, the audit itself is merely a process. The "crown" or final result of this long procedure—starting from the delivery of the Audit Warrant (SP2), testing of cash/goods flows, to the closing conference—is the issuance of a legal product known as the Tax Assessment Letter (Surat Ketetapan Pajak - SKP).

For Taxpayers, understanding the types, characteristics, and implications of each SKP is crucial. An SKP is not just a bill; it is a state determination that possesses executorial power and a statute of limitations. Furthermore, with the enactment of Minister of Finance Regulation Number 15 of 2025 (PMK 15/2025) which aligns procedures with the Coretax System, there are new affirmations, particularly regarding the integration of Land and Building Tax (PBB) into the general audit regime.

This article will thoroughly dissect the variety of SKPs that may be issued post-audit, the legal basis for their issuance, and the strategic implications for Taxpayers.

1. Legal Basis and Philosophy of Assessment

Fundamentally, based on Article 12 of the KUP Law, tax is in principle payable at the time the tax becomes due, at the end of the Tax Period, or the end of the Tax Year. However, the amount of tax payable only becomes "fixed" and legally binding administratively when the tax authority (fiskus) issues an SKP based on audit results.

PMK 15 of 2025 asserts that the Audit Result Report (LHP) is the absolute basis for issuing a Tax Assessment Letter [PMK 15 Year 2025, Article 20 paragraph 3]. Without an LHP compiled based on Audit Working Papers (KKP), an SKP is procedurally defective.

In the latest regime, SKPs are classified into several main types:

2. Underpayment Tax Assessment Letter (SKPKB)

This is the type of assessment most frequently issued and most feared by Taxpayers.

Definition: SKPKB is a tax assessment letter that determines the amount of principal tax, tax credit, amount of principal tax underpayment, amount of administrative sanctions, and the amount of tax still payable [SDSN UU KUP 2023, Point 16; PP 50 Year 2022, Article 1 Point 17].

Issuance Conditions:

Based on Article 13 of the KUP Law and PMK 80 of 2023, an SKPKB is issued if:

1. Based on audit results or other information, the tax payable is not or underpaid.
2. The Tax Return (SPT) is not submitted within the specified time and, after a written warning, is still not submitted.
3. Bookkeeping obligations (Article 28/29 of the KUP Law) are not met so that the tax payable cannot be known (Ex-Officio Issuance).

3. Additional Underpayment Tax Assessment Letter (SKPKBT)

SKPKBT is the "second nightmare" because it is issued for tax that has already been assessed previously.

Definition: SKPKBT determines the addition to the amount of tax that has been previously assessed [SDSN UU KUP 2023, Point 17; PP 50 Year 2022, Article 1 Point 18].

Absolute Requirement: Novum (New Data)

SKPKBT can only be issued if new data (novum) and/or data that was originally unrevealed is found, causing an increase in tax payable [PP 50 Year 2022, Article 24].

• Re-Audit: The issuance of SKPKBT must be preceded by a Re-Audit (Pemeriksaan Ulang) [PMK 15 Year 2025, Article 25 paragraph 1].

Severe Sanctions: The tax amount in SKPKBT is added with an administrative sanction in the form of a 100% surcharge of the amount of such tax underpayment [PP 50 Year 2022, Article 22].

4. Nil Tax Assessment Letter (SKPN)

Definition: SKPN is issued if the amount of principal tax equals the amount of tax credit, or no tax is payable and there is no tax credit [SDSN UU KUP 2023, Point 18; PP 50 Year 2022, Article 1 Point 19].

Issuance Context: SKPN is often the result of a restitution audit where the examiner recognizes only part of the tax credit so that the value exactly covers the tax debt.

5. Overpayment Tax Assessment Letter (SKPLB)

Definition: SKPLB determines the amount of overpayment of tax because the amount of tax credit is greater than the tax payable [SDSN UU KUP 2023, Point 19; PP 50 Year 2022, Article 1 Point 20].

Restitution Audit (Article 17B KUP Law): SKPLB is the legal product awaited by Taxpayers applying for restitution. Keep in mind the crucial deadline: The DGT must issue the SKP no later than 12 months after the application is received complete [PP 50 Year 2022, Article 10].

6. PBB Tax Assessment Letter (SKP PBB)

One of the significant integrations in PMK 15 of 2025 is the affirmation regarding SKP PBB under one audit regulation umbrella.

Definition: PBB Tax Assessment Letter is a letter that determines the amount of principal Land and Building Tax (PBB) or the difference in principal PBB, the amount of administrative fines, and the amount of PBB still payable [PMK 15 Year 2025, Article 1 Point 43].

Issuance Conditions: SKP PBB is issued if the amount of PBB payable is greater than the amount of tax calculated based on the SPOP submitted by the Taxpayer [PMK 15 Year 2025, Article 20 paragraph 3].

7. Vital Procedures: From LHP to SKP

The issuance of an SKP does not happen in a vacuum. It is the downstream of a strict administrative process:

1. Audit Result Report (LHP): The Examiner compiles the LHP based on Audit Working Papers (KKP) [PMK 15 Year 2025, Article 20 paragraph 1].
2. Calculation Note (Nothit): Based on the LHP, the examiner creates a Calculation Note as the technical basis for issuing the SKP.
3. Obligation of Final Discussion (PAHP): Before the SKP is issued, the Examiner must deliver the SPHP and conduct a Closing Conference. If skipped, the SKP is potentially void by law.
4. Statute of Limitations: SKP can only be issued within a period of 5 (five) years after the tax becomes due [PP 50 Year 2022, Article 27 paragraph 3].

8. Implications for Taxpayers and Strategy

The issuance of an SKP triggers a series of new rights and obligations:

• Pay: If agreed, the Taxpayer must pay off the SKPKB/SKPKBT within 1 month.
• File Objection: If disagreeing, the SKP can be filed for Objection to the Regional Office of DGT within 3 months from the date sent [PMK 118 of 2024, Article 10].
• Importance of Quality Assurance: Before the SKP is issued, if there is a legal basis dispute, the Taxpayer has the right to request a discussion with the Quality Assurance Team [PMK 15 Year 2025, Article 19].

Conclusion

The Tax Assessment Letter (SKP) is the manifestation of the state's authority to collect underpaid taxes or return Taxpayer rights. In the era of PMK 15 of 2025, the issuance procedures are increasingly integrated and transparent. Taxpayers must understand that the validity of an SKP relies heavily on adherence to prior audit procedures. Receiving an SKP is not the end; it is the gateway to settling obligations or the beginning of legal objection efforts to seek justice.

Reference:

1. SDSN UU KUP 2023 (Law on General Provisions and Tax Procedures).
2. PP Number 50 of 2022 (Exercise of Rights and Fulfillment of Tax Obligations).
3. PMK Number 15 of 2025 (Tax Examination).
4. PMK Number 80 of 2023 (Issuance of Tax Assessment Letters).
5. PMK Number 118 of 2024 (Objection and Cancellation Procedures).
6. SE-28/PJ/2017 (Audit Result Reports Guidelines).
7. Tax Audit Blue Book.
8. Video Transcript "RTD - Thorough Discussion of Tax Audit 2025".