GST SAC Code

GST SAC Code: The Complete 2026 Guide for Service Businesses in India

A SAC (Services Accounting Code) is the six-digit classification code every GST-registered service supplier must quote on their tax invoice, in GSTR-1 Table 12, and inside every e-invoice JSON payload. It determines the applicable GST rate, drives the HSN/SAC summary in your returns, and — since GSTN's AI-driven mismatch engine became fully operational — directly affects whether your customer's input tax credit (ITC) claim survives scrutiny. Getting it right is not a one-time exercise. It requires a maintained master list and a billing system that prevents manual entry errors at invoice time.

What Is a SAC Code and How Does It Differ from HSN?

SAC = Services Accounting Code. The Central Board of Indirect Taxes and Customs (CBIC) developed SAC codes for GST by adapting the United Nations Central Product Classification (UN CPC) system to Indian service categories. Every taxable service in India is assigned a unique SAC that simultaneously describes the service and determines its GST treatment.

HSN = Harmonised System of Nomenclature, used for goods. The two systems run in parallel but are entirely separate:

A persistent mistake in ERP-driven businesses is populating HSN codes on service line items — especially in mixed invoices where goods and services are billed together. Each line item needs the correct code from the correct universe. An HSN code on a service line is structurally wrong even if it passes through IRP validation by accident.

The Six-Digit SAC Structure Decoded

Every SAC code follows a three-tier hierarchy:

`` 9 9 | X X | X X ↑ ↑ ↑ Service Major Specific marker group sub-type (always (e.g., (e.g., 99) 54 = 11 = constr.) residential) ``

Example A — SAC 995411 (Construction of new residential buildings):

• 99 → This is a service (not a good)
• 9954 → Construction services (the major sub-group)
• 995411 → Specifically, construction of new residential buildings

Example B — SAC 998315 (Computer programming services):

• 99 → Service
• 9983 → Other professional, technical and business services
• 998315 → Computer programming services specifically

This hierarchy is practically useful. When you cannot locate the exact six-digit code for an unusual service, work downward: identify the broadest major group (four digits), then find the most accurate sub-type (six digits). If two codes could reasonably apply, choose the one that most closely describes the dominant economic activity of the transaction and document your reasoning.

SAC Code List: High-Use Codes Every Service Business Needs

The following tables cover the codes you will encounter most frequently. Always verify the applicable GST rate against the current CBIC notification before finalising — rates have been revised multiple times since 2017.

Construction and Real Estate (9954, 9972)

*Rate depends on project type, ITC availability and applicable notification. Confirm before use.

IT, Software and Technology Services (9983)

This cluster is the source of the most classification disputes in the technology sector. A product-led SaaS company may use 998315 or 998316; a services-led IT firm doing system integration typically lands on 998314. The contract scope-of-work, the nature of the deliverable, and the dominant economic activity are your classification anchors — not company preference.

Legal, Accounting and Professional Services (9982)

Note that legal services supplied by an advocate or a firm of advocates to a business entity attract GST under Reverse Charge Mechanism (RCM) — the recipient, not the advocate, pays the tax. Using SAC 998211 on a B2B invoice must be accompanied by a clear "RCM applicable" notation.

Financial Services (9971) and Telecom (9984)

SAC Code on Invoices in FY 2026-27: The Exact Rules

Under Notification No. 78/2020-Central Tax (as amended), the number of SAC digits required on a tax invoice is tied to your aggregate turnover in the preceding financial year:

If your billing software defaults to four-digit codes and your turnover has crossed Rs. 5 crore, every B2B invoice you raise is technically non-compliant. The fix is a one-time item-master update — not a manual override at billing time.

Step-by-Step: Quoting SAC Correctly on Every Invoice

1. Identify the primary service in the transaction — one invoice may have multiple service lines, each with its own SAC.
2. Look up the six-digit code in the CBIC SAC tariff schedule (available on the CBIC website under GST rate notifications).
3. Confirm the current GST rate for that code against the rate notification — do not rely on a cached or printed version from a previous year.
4. Enter the SAC on the invoice adjacent to the line-item description: e.g., "IT Consulting Services — SAC: 998314".
5. Report the SAC in GSTR-1 Table 12 (HSN/SAC-wise summary of outward supplies) — the SAC, UQC (unit of quantity code: NOS for services), total value and tax must match the invoice.
6. For e-invoices: verify that the HsnCode field in the IRP JSON payload exactly matches the invoice. A mismatch between the e-invoice payload and the GSTR-1 entry triggers a reconciliation flag in your recipient's GSTR-2B.
7. Archive the CBIC notification or circular you relied on for the classification — one line of documentation that becomes invaluable during scrutiny or audit.

E-Invoicing and SAC Codes: The 2026 Reality

The e-invoicing mandate has been progressively tightened since 2020, and as of the most recent CBIC notification the threshold stands at Rs. 5 crore aggregate turnover — verify this against the current notification, as the GST Council has flagged further reductions. Any business above the applicable threshold must generate an Invoice Reference Number (IRN) from the IRP before the invoice is legally valid.

Under e-invoicing, SAC discipline is no longer optional:

• IRP validation is real-time and unforgiving. A SAC field with fewer than six digits where six are required, or an HSN code placed in the service code field, will cause immediate IRN generation failure. Your billing run stalls, your customer's payment clock starts late, and you bear the contractual cost.
• GSTN's AI mismatch engine cross-references SAC against rate. If you charge 18% on a line coded to an exempt SAC, or 5% on a line where the SAC's standard rate is 18%, a mismatch flag appears in your customer's GSTR-2B with a risk marker. The customer then has to file a written explanation or risk ITC denial.
• Auto-population in GSTR-2B. Your customer's ITC is now auto-populated based on the e-invoice data — including the SAC. An incorrect SAC that maps to an exempt or differently-rated service creates a GSTR-2B entry that does not match the customer's actual purchase, triggering a reconciliation dispute that neither party budgeted for.

Worked Example: A Mixed-Services Invoice — Wrong and Right

The Situation

A Delhi-based IT firm with aggregate turnover of Rs. 12 crore in FY 2025-26 raises a Rs. 10,00,000 invoice (plus 18% IGST) to a Bengaluru corporate client covering three service lines:

• Software development work: Rs. 7,00,000
• Post-launch IT support and maintenance: Rs. 2,00,000
• Project management consulting: Rs. 1,00,000

What Went Wrong

The billing executive used a single four-digit code 9983 across all three lines. Because the firm's turnover exceeds Rs. 5 crore, six-digit SAC is mandatory. The IRP rejected the e-invoice, creating a three-day billing delay and a strained client relationship.

After correcting the digit count, the executive applied 998311 (management consulting) to all three lines — the wrong code for two of them.

Consequences:

• Output IGST (Rs. 1,80,000) was correctly calculated at 18% — so the tax payment itself was correct.
• GSTN's analytics flagged a mismatch: Rs. 7,00,000 of software development coded as management consulting does not fit the firm's activity profile. A risk query was generated in the Bengaluru client's GSTR-2B dashboard.
• The client's finance team spent two days documenting the ITC claim — cost that falls entirely on the recipient and damages the supplier relationship.

The Correct Treatment

Each line carries its own six-digit SAC in the e-invoice JSON payload and in GSTR-1 Table 12. No mismatch. The client's Rs. 1,80,000 ITC flows cleanly into GSTR-2B. The three-day IRN delay and the two-day client reconciliation effort — both entirely avoidable — had a combined opportunity cost easily exceeding Rs. 20,000 in billing-team time.

Common Mistakes and Pitfalls to Avoid

Using the Four-Digit Code When Six Are Mandatory

If your turnover crossed Rs. 5 crore in the preceding financial year, four-digit SAC on a B2B invoice is non-compliant. Audit it in your billing software today.

Dumping Everything into SAC 9983

The catch-all tendency: all professional services are bundled under the broad four-digit 9983. This code has more than 30 six-digit sub-codes. GSTN's analytics use the specific code for risk profiling; using the broad code consistently marks your account as a classification risk.

Ignoring RCM Obligations Triggered by SAC

Legal services (998211), security services, goods transport agency services, and other categories attract RCM. If you receive these services and the supplier uses the correct SAC, your GST system should auto-flag the RCM liability. A wrong SAC on the supplier's invoice can cause you to miss an RCM payment obligation, which carries interest under Section 50 of the CGST Act at 18% per annum.

Applying an Outdated Rate to a Valid SAC

GST Council rate revisions happen multiple times a year. The rate that applied to SAC 995411 in FY 2022-23 may differ from the rate in FY 2026-27. A SAC-to-rate mapping is not a set-and-forget artifact — it must be reviewed after every GST Council meeting that touches services rates.

Inconsistent SAC Between Invoice and GSTR-1

If the e-invoice payload carries 998315 but your GSTR-1 Table 12 reports 998311, GSTN's reconciliation engine flags a discrepancy. Maintain a single source of truth: the item master in your billing or ERP system must be the one source that populates both the invoice and the return automatically.

No Documentation for Judgment Calls

When you make a reasonable but non-obvious classification decision — for instance, treating a bundled SaaS-plus-support contract as a composite supply under 998316 — write a one-page file note referencing the contract, the principal-supply test, and the CBIC circular you relied on. This note is your first line of defence in a Section 65 audit and can resolve a scrutiny notice under Section 61 in a single correspondence cycle.

Composite and Mixed Supplies: The SAC Classification Minefield

Bundled service offerings create classification questions that the six-digit SAC alone cannot answer — you must first determine the supply type.

Composite supply: Two or more supplies that are naturally bundled and ordinarily supplied together. The SAC of the principal supply governs the entire bundle. Example: an AMC contract covering both preventive maintenance visits (service) and replacement parts (goods) is a composite supply if customers would not realistically buy the labour without the parts. The principal supply determines the SAC and rate for the whole contract value.

Mixed supply: Two or more supplies that could be independently purchased but are sold together for a single price. The SAC of the component attracting the highest GST rate applies to the entire bundle.

Practical workflow for any bundled contract:

1. List every component — service lines and goods lines — in the contract.
2. Ask: would a customer typically purchase any component independently? If no, it is likely composite.
3. For composite: identify the principal supply and apply its SAC.
4. For mixed: identify the highest-rate component and apply its SAC.
5. Document the analysis, cite any applicable CBIC circular, and retain the customer's scope-of-work document.
6. Apply the same classification uniformly across all invoices under that contract — inconsistency across billing periods creates audit exposure.

Cross-Border Services: SAC, Place of Supply, and FEX Alignment

For exported or imported services, SAC classification interacts with place-of-supply rules under Sections 12 and 13 of the IGST Act, 2017. An error here does not just affect the rate — it can change the taxability entirely.

Export of services (zero-rated): To qualify under Section 2(6) of the IGST Act, all five conditions must be satisfied, including payment received in convertible foreign exchange (FEX) and the service being performed for a recipient outside India. The SAC on the export invoice must accurately describe the service exported. Refund claims under Rule 89 that carry an SAC inconsistent with the nature of the exported service have been questioned by GST officers during RFD-01 processing — holding up refunds for months and locking working capital.

Import of services (RCM under Section 5(3) of IGST Act): When you receive services from a foreign supplier — cloud subscriptions, overseas legal counsel, foreign management consultants — you account for IGST under RCM. The SAC you assign in your RCM self-invoice and GSTR-3B must correctly describe the service imported. A wrong SAC can create a GSTR-3B versus GSTR-2A mismatch for inward supplies and attract a notice under Section 61.

Cross-border alignment checklist:

• [ ] SAC matches the service actually delivered, not just the foreign entity's billing description
• [ ] Place of supply correctly determined under Section 12 (B2C) or Section 13 (B2B/default rules)
• [ ] Export invoices carry the required endorsement ("supply meant for export without/with payment of IGST")
• [ ] LUT or bond is active and referenced on zero-rated export invoices
• [ ] RCM self-invoice raised on the date of payment or entry in books, whichever is earlier
• [ ] SAC in GSTR-3B Table 4 (inward supplies under RCM) matches the self-invoice

How to Build a SAC Code Master That Actually Gets Used

A SAC master is a table — maintained in a spreadsheet or directly in your ERP item master — that maps every service you supply to its classification details. Here is the minimum structure:

Implementation in six steps:

1. Export your current service/product item master from your billing software or ERP.
2. For every service line item, verify or assign the correct six-digit SAC.
3. Cross-check each SAC's current GST rate against the applicable rate notification — do not rely on memory or a guide more than one GST Council meeting old.
4. Note any RCM, zero-rating, or exempt nuances per service line.
5. Import the updated master back into the system and lock the SAC field so it cannot be overridden manually at invoice time. Human error at billing time is the largest single source of SAC mistakes.
6. Assign a named owner — one person whose quarterly task is to review the master after each GST Council meeting and update codes or rates as needed.

Embedding SAC codes in the item master rather than selecting them at invoice creation time eliminates the high-pressure, high-error single biggest source of classification mistakes in most service businesses.

Key Takeaways

• SAC codes always start with 99 and are six digits; the last four digits identify the service sub-group and specific type. They are the service equivalent of HSN codes for goods — never use an HSN code on a service invoice line.
• Six-digit SAC is mandatory on B2B invoices for taxpayers with aggregate turnover above Rs. 5 crore in the preceding FY, and on all e-invoices regardless of turnover — the IRP JSON HsnCode field requires it.
• A wrong SAC directly endangers your customer's ITC: GSTN's mismatch engine flags rate inconsistencies in auto-populated GSTR-2B, forcing your customer to defend their credit — a compliance cost you have imposed on them.
• Composite and mixed supply analysis must be done contract by contract: the principal-supply or highest-rate rule determines the single SAC that governs the entire bundled offering.
• Cross-border service errors surface late — at refund or audit stage — and can lock working capital for months. SAC, place of supply, FEX receipt, and LUT status must all align before raising the invoice.
• RCM obligations are triggered by SAC classification: legal, security, and transport services are common examples where the recipient accounts for GST and a wrong supplier SAC can cause the recipient to miss the liability entirely, attracting Section 50 interest.
• Build a SAC master, lock it in your billing system, and review it quarterly. The 30 minutes this takes after each GST Council meeting is the single cheapest, highest-return GST compliance investment any service business can make.