GST · SAC 998331 · FY 2026–27

SAC 998331: Engineering Advisory Services

SAC 998331 (Engineering Advisory Services) is taxed at 18% GST: 9% CGST + 9% SGST when you and your client are in the same state, 18% IGST when you are not, and 0% on exports under a Letter of Undertaking (LUT). Covers: General engineering consulting and advisory work.

Rate source: Notification 11/2017-Central Tax (Rate), Heading 9983

18%

Domestic
0% export (LUT)

Heading

9983 — professional & technical services

Domestic rate

18% (9+9 / IGST)

Export (LUT)

Reverse charge

No — forward charge

What falls under 998331

Engineering consulting independent of specific civil, electrical, or mechanical disciplines — strategic engineering advisory, technology selection, technical due diligence.

Engineering advisory

Technical due diligence

Technology selection consulting

Not this code — structural and building engineering for residential, commercial and institutional buildings → 998332 · process engineering for industrial and manufacturing facilities → 998333 · engineering for power generation, transmission and distribution projects → 998335

On the invoice

Invoice INV-0092SAC 998331

Engineering advisory₹1,40,000

CGST @ 9% + SGST @ 9% (same state — else IGST 18%)+ ₹25,200

Amount due₹1,65,200

Same work for a foreign client under LUT: IGST 0%, with the zero-rating declaration on the face of the invoice.

Suresh, a Pune-based engineering consultant (MH, state code 27), runs technical due diligence for a Mumbai PE firm (MH, state code 27). Rs. 1,40,000. Intra-state → CGST 9% + SGST 9%.

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FAQ

Do I have to print the SAC code on my invoices?

Depends on turnover: up to Rs. 5 crore, the 4-digit SAC (9983) is enough on B2B invoices; above that, 6 digits are required. Printing the full 6-digit code (998331) everywhere is simplest and never wrong.

Under Rs. 20 lakh turnover — do I need to register and charge 18%?

Below Rs. 20 lakh aggregate turnover, registration is optional for pure service providers — you invoice without GST entirely. The Rs. 10 lakh threshold applies in only four special-category states (Manipur, Mizoram, Nagaland, Tripura), not the eleven usually listed online. Once registered, 18% applies to every domestic invoice regardless of turnover.

Wrong SAC code on past invoices — how bad is it?

If the rate charged was right, it is a clerical issue — fix it going forward. A wrong code with a wrong rate is the real problem; that needs a credit note and a corrected invoice. Mismatched SACs also cause GSTR-1 Table 12 disclosure issues and can trigger ITC audit queries at the client end.

Does SAC 998331 change under GST 2.0?

No. The September 2025 rate rationalisation reshuffled the goods slabs; professional and technical services stayed at the 18% standard rate, and export zero-rating under LUT is unchanged.

Notification reference: Notification 11/2017-CT(R) dated 28 June 2017 — the services rate table, at the serial for the code's heading (9982, 9983, 9985, 9992 or 9996 as applicable), as amended, including by Notification 15/2025-CT(R) (GST 2.0, from 22 September 2025).

For the CA reading this

The deadline sheet you already send, with your name on it

Every statutory date for the month — GST returns, advance tax, and the dates your client's own customers owe them: when the TDS they withheld must reach the department, and when the certificate is due. Add your firm's name and forward it as it stands. No signup, no email, nothing to accept.

Firm name (optional)Month

Download the image

The image is the one that travels on WhatsApp. Dates are statutory, not advice — the sheet says which rows bind whom.

Sources

Rates as notified for FY 2026–27 and can change. General information, not tax advice. Verify with your CA before you file.

Billing 998331 as a freelancer

Use Case

GST on Export of Services Without an LUT: What It Costs and What You Can Still Do

9 min read →Tax Guide

GST Registration Limit for Freelancers: Have You Already Crossed It?

9 min read →Tax Guide

Your Client Wants a GST Bill and You Have No GST Number

9 min read →

Related codes

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