GST Invoice for Services India — Format, SAC Code & Rules 2026

Service providers in India — consultants, designers, developers, chartered accountants, architects, coaches, photographers, event managers, and many others — must issue a GST invoice for every taxable service they provide if they are GST registered. Unlike goods invoices that need HSN codes, service invoices require SAC (Services Accounting Code) codes. Getting these right is essential for your clients to claim Input Tax Credit (ITC) and for you to file correct GST returns.

This guide explains the exact GST invoice format for services in India, which SAC codes apply to common professions, the time limit for issuing service invoices, and how to create a fully GST-compliant service invoice for free using Ozydo.

GST Rate for Services in India — The 18% Rule

Most professional services in India attract 18% GST. This is the default rate for services that are not specifically placed in a different slab or exempted. Here are the key service categories and their GST rates:

Mandatory Fields in a GST Service Invoice

A GST invoice for services must follow Rule 46 of CGST Rules 2017. Here are all the mandatory fields:

1. 1Header: 'Tax Invoice' — must appear prominently on the document
2. 2Service provider's name, address, and GSTIN
3. 3Invoice number — sequential, unique, up to 16 characters
4. 4Invoice date
5. 5Client's name, address, and GSTIN (for B2B transactions)
6. 6Description of service provided
7. 7SAC code — Services Accounting Code for the type of service
8. 8Taxable value of service (before GST)
9. 9GST rate applied (e.g., 18%)
10. 10CGST amount (9%) and SGST amount (9%) for intra-state — OR IGST (18%) for inter-state
11. 11Place of supply — state name and code
12. 12Total invoice amount in figures and words
13. 13Payment details — bank account with IFSC code or UPI ID
14. 14Authorized signature

Time Limit for Issuing a GST Service Invoice

For services, the GST invoice must be issued within 30 days of the date of supply of services. For banking companies, financial institutions, and NBFCs, this limit is 45 days. Missing this deadline means the invoice may not be valid for ITC in the month it should have been claimed.

SAC Code — What It Is and How to Find It

SAC (Services Accounting Code) is a six-digit classification code used under GST to identify the type of service being supplied. It is similar to HSN codes for goods. SAC codes are maintained by the CBIC (Central Board of Indirect Taxes and Customs) and are based on the United Nations' Central Product Classification (CPC).

• SAC codes are mandatory on invoices for businesses with annual turnover above ₹5 crore.
• For turnover between ₹1.5 crore and ₹5 crore — 2-digit SAC (chapter level) is mandatory.
• For turnover below ₹1.5 crore — SAC code is optional but recommended.
• You can find SAC codes on the GST portal: gst.gov.in → Services → HSN/SAC → Search.
• Common starting codes: 99 (all services start with 99 in the SAC system).

Service Invoice Example — Freelance Web Developer

GST Invoice for Services — Intra-State vs Inter-State

The place of supply determines whether you charge CGST + SGST or IGST on your service invoice. For most services, the place of supply is the location of the recipient (your client's state). If you and your client are in the same state — charge CGST + SGST. If in different states — charge IGST. Ozydo automatically detects the correct tax split based on the supplier and client states you enter.

B2B vs B2C Service Invoices

• B2B invoices (to GST-registered clients) — client's GSTIN is mandatory. Client claims ITC.
• B2C invoices (to unregistered individuals) — GSTIN is not required. For supplies above ₹2.5 lakh, full client address is needed.
• For B2C below ₹2.5 lakh — only client name needed on the invoice.
• Always issue a proper invoice even for B2C — it's required for your GSTR-1 filing.