A GST tax invoice for consultancy services needs your name, address and GSTIN, a unique invoice number (up to 16 characters), the date, the client's details and GSTIN, the SAC code, a description, taxable value, tax rate and amount, place of supply, reverse charge status and a signature.
Rule 46 fields · SAC codes · CGST + SGST or IGST · Last reviewed 29 Oct 2026These fields come from rule 46 of the CGST Rules, 2017. Issue the invoice within 30 days of supplying the service (rule 47). Most consultancy is taxed at 18%: CGST 9% + SGST 9% if the client is in your state, IGST 18% if not.
Last reviewed 29 Oct 2026. This is general information, not tax advice. GST rules change, so check your invoices with your CA.
Related: Free GST invoice template (Excel and PDF), How to track billable hours, GST invoice for export of services under LUT.
Rule 46 lists the particulars as clauses (a) to (s). Not all of them apply to every invoice. The table explains each one in plain words for a consultancy billing in India.
| Rule 46 clause | What to put on the invoice | Needed on a consultancy invoice? |
|---|---|---|
| (a) | Your legal name, address and GSTIN | Always |
| (b) | Invoice number: consecutive, up to 16 characters, letters, numbers, "-" and "/" only, unique for the financial year | Always |
| (c) | Date of issue | Always |
| (d) | Client's name, address and GSTIN (or UIN) if the client is registered | Always for a registered client |
| (e), (f) | For an unregistered client: name, address, delivery address, and the state name and code. Required when the taxable value is ₹50,000 or more; below that, only if the client asks | Only for unregistered clients |
| (g) | HSN code for goods or SAC code for services (see the digits rule below) | Yes |
| (h) | Description of the service | Always |
| (i) | Quantity and unit | Goods only. For services you can still show hours or days, but the rule asks for quantity "in case of goods" |
| (j) | Total value of the supply | Always |
| (k) | Taxable value, after any discount | Always |
| (l) | Rate of tax: CGST and SGST (or UTGST), or IGST, and cess if any | Always |
| (m) | Amount of each tax | Always |
| (n) | Place of supply with the state name, for inter-state supplies | Inter-state invoices. Many firms show it on every invoice so the tax split is easy to check |
| (o) | Delivery address, if different from the place of supply | Rarely for services |
| (p) | Whether tax is payable on reverse charge | Always show "Reverse charge: Yes/No" |
| (q) | Signature or digital signature of you or your authorized representative | Yes, with an exception for electronic invoices (see below) |
| (r) | QR code with the Invoice Reference Number (IRN) | Only if you must e-invoice |
| (s) | A set declaration, if your turnover is above the e-invoicing limit but you are exempt from e-invoicing | Only in that case |
Rule 48(2) also says a services invoice is prepared in two copies, marked "ORIGINAL FOR RECIPIENT" and "DUPLICATE FOR SUPPLIER". (This does not apply to e-invoices under rule 48(4).)
For services where you and the client are both in India, section 12(2) of the IGST Act sets the general rule:
Then compare the place of supply with your own state:
The first two digits of a GSTIN are the state code, so you can check this quickly. Maharashtra is 27 and Karnataka is 29.
Section 12 has separate rules for some services, such as services linked to immovable property, events, training and transport. Plain management consulting usually falls under the general rule. Check unusual cases with your CA. Exports to clients outside India follow different rules (the IGST Act's section 13 and the export endorsement in rule 46) and are not covered here.
Services use the Services Accounting Code (SAC). The codes below are from the Scheme of Classification of Services published by CBIC and the GST Council.
Watch out: some templates online list 998312 as accounting, 998313 as tax and 998314 as IT consulting. That mapping does not match the CBIC scheme. Accounting and tax work sit under heading 9982, not 9983.
Rate. Heading 9983 "other professional, technical and business services" is listed at 9% CGST (so 18% in total) in Notification 11/2017-Central Tax (Rate), dated 28 June 2017, serial number 21, item (ii). The September 2025 rate changes (Notification 15/2025-Central Tax (Rate)) reworded that item but did not change its rate. Confirm the rate for your exact service with your CA.
Notification 78/2020-Central Tax (in force from 1 April 2021) sets the digits by your aggregate turnover in the previous financial year:
The table sets the number of digits for your turnover. Some firms below the limit show the full 6 digits even when 4 are required, because the longer code describes the service more exactly. The notification does not say whether more digits than required are allowed, so confirm with your CA before you use them.
Every tax invoice must say whether tax is payable on reverse charge (rule 46(p)). For a consultancy's own fees to a client, this is usually "No": you charge the GST.
Reverse charge mostly shows up on what a consultancy buys. For example, legal services from an advocate or a firm of advocates to a business entity are on the reverse charge list (Notification 13/2017-Central Tax (Rate)), so the business pays the GST instead of the advocate. Ask your CA which of your purchases fall under it.
Rule 46(q) asks for your signature or digital signature, or that of an authorized representative. A proviso to rule 46 says no signature is needed on an electronic invoice issued in line with the Information Technology Act, 2000. Whether your PDF invoice counts as one is a question for your CA. If you're unsure, sign it or use a digital signature.
If you are under the composition scheme (section 10 of the CGST Act) or your service is exempt, you issue a bill of supply instead of a tax invoice (section 31(3)(c)). Rule 49 asks for fewer fields:
No tax is shown.
Example only. All businesses, GSTINs and figures below are made up.
Supplier: Sahyadri Strategy Advisors LLP (fictional), Baner, Pune, Maharashtra. GSTIN 27AAAAA0000A1Z0 (dummy). Aggregate turnover last FY: ₹3 crore, so the table asks for a 4-digit SAC and e-invoicing does not apply. Sahyadri shows 6 digits on these invoices; see the note on extra digits above, and check this choice with your CA.
Maths: ₹1,60,000 × 18% = ₹28,800 IGST. ₹1,60,000 + ₹28,800 = ₹1,88,800.
Amount in words (optional, but clients like it): Rupees One Lakh Eighty-Eight Thousand Eight Hundred only.
Maths: ₹80,000 × 9% = ₹7,200 CGST, and the same again for SGST. Total GST ₹14,400 (18%). ₹80,000 + ₹14,400 = ₹94,400.
Both invoices end with the bank details for payment, the line "For Sahyadri Strategy Advisors LLP", and the signature of an authorized partner. The two numbers run one after the other in the same FY series.
If the Pune client deducts TDS when paying, that is an income-tax matter. It does not change the invoice: you still bill ₹94,400 and record the TDS when the payment arrives.
Copy this layout, or download our free GST invoice template in Excel and PDF, which compares the two state codes to work out CGST + SGST or IGST. (That's the downloadable sheet, not the Trakkar app.)
| Block | Fields |
|---|---|
| Header | "TAX INVOICE", ORIGINAL FOR RECIPIENT / DUPLICATE FOR SUPPLIER |
| Your details | Legal name, address, GSTIN, state and code |
| Invoice details | Invoice no. (max 16 characters), date, due date, reverse charge Yes/No |
| Client details | Name, address, GSTIN or UIN, state and code |
| Place of supply | State name and code |
| Lines | Description, SAC, hours/days (optional for services), rate, discount, taxable value |
| Tax | CGST rate and amount + SGST/UTGST rate and amount, or IGST rate and amount |
| Totals | Taxable value, total tax, invoice total, amount in words (optional) |
| Footer | Bank details, terms, signature or digital signature of authorized signatory |
| If e-invoicing applies | IRN and QR code |
Trakkar is time tracking, attendance and project software for Indian service businesses, used by 100+ teams. It includes GST invoicing for your own clients:
What Trakkar doesn't do: it doesn't add SAC codes or place of supply, and it doesn't split tax into CGST, SGST and IGST automatically. Trakkar doesn't file GST returns or generate e-invoice IRNs. You add invoice lines yourself. Check with your CA that your invoices carry every field your business needs.
Trakkar has one plan, Premium, at ₹120 per user a month + GST. Try it free for 14 days with no card needed, and there's no setup fee. See pricing or book a 30-minute demo.
Running a practice? See time tracking software for CA firms. Billing by the hour? Read how to track billable hours.
Other high-intent guides for Indian teams.
A tax invoice with your name, address and GSTIN; a unique invoice number up to 16 characters; date; client name, address and GSTIN; SAC code; description; taxable value; tax rate and amount; place of supply; reverse charge status; and a signature. These come from rule 46 of the CGST Rules, 2017.
Time tracking, attendance and GST invoicing for your team, priced in rupees. 14-day free trial, no card needed.
