Consultants, chartered accountants, company secretaries, and cost accountants form the backbone of India's business advisory ecosystem.

Yet many professionals struggle with their own invoicing. Project-based work, retainers, hourly billing, and success fees all require different invoicing approaches.

This guide is for management consultants, financial advisors, CAs, CSs, and cost accountants who want to professionalize their billing.

Stop fighting with invoice templates.

Generate a legally compliant, highly professional invoice in under 60 seconds.
No signup required to start. No credit card. Just type, send, done.

Show me how

GST for consultants and accounting professionals

Registration threshold: ₹20 lakh annual turnover (₹10 lakh in special category states).
SAC codes: Management consulting — 9983, Accounting/auditing — 9982, Tax consulting — 9982, Financial advisory — 9983.
GST rate: 18% for all professional services (CGST 9% + SGST 9% for intra-state, IGST 18% for inter-state).
Reverse Charge: If you are a CA/CS/CWA providing services to a company or firm, RCM may apply.
Export of services: Advisory to foreign clients is zero-rated. Issue invoice in foreign currency, maintain FIRC, and file LUT.

Common fee structures and how to invoice them

Monthly Retainers: Fixed fee for ongoing advisory. Invoice on the 1st of each month for that month's services.
Project-based Fees: One-time fee for a defined project. Invoice 50% upfront, 50% on delivery, or milestone-based.
Hourly Billing: Common for advisory and consulting. Maintain time sheets. Invoice monthly with detailed time entries.
Value-based Fees: Fee linked to outcome. Invoice upon achieving the agreed outcome with calculation clearly shown.
Reimbursements: Travel, accommodation, software subscriptions — pass through at cost or with a small markup.

The complete professional services invoice

Your credentials: Name, qualifications (CA/CS/MBA/etc.), firm name, registration numbers, address, phone, email, GSTIN.
Client details: Company name, address, contact person, and GSTIN. For individuals, PAN may be required.
Engagement reference: Quote the proposal number, engagement letter date, or project code.
Service period: 'Services rendered during March 1-31, 2026' or 'Project completed on March 15, 2026'.
Detailed service breakdown: 'GST return filing for 3 GSTINs', 'Preparation of financial statements'.
Professional fees subtotal: Sum of all service charges before GST.
Reimbursements: Listed separately with descriptions and amounts.
GST calculation: Show taxable value, SAC code, GST rate, and tax amount.
Total payable: In figures and words. Include due date and payment terms.
Payment details: Bank account, IFSC, UPI ID. For large firms, include payment link or portal details.

Special considerations for audit and assurance work

Statutory audit fees: Usually fixed annually. Invoice after audit completion and before AGM.
Internal audit fees: Often quarterly. Invoice at the end of each quarter with summary of work performed.
Tax audit fees: Linked to tax filing deadlines. Invoice after tax audit report (Form 3CD) is finalized.
Certification work: Net worth certificates, turnover certificates — invoice upon issuance of certificate.
Peer review compliance: If you are subject to peer review, ensure your invoicing system maintains documentation standards.

Managing client expectations and payments

Clear engagement letters: Define scope, fees, billing frequency, and payment terms before starting work.
Advance billing for new clients: For clients with no payment history, take 50-100% advance.
Regular billing for ongoing work: Monthly billing for retainers and long projects.
Payment follow-up protocol: Day 1 after due date — friendly reminder. Day 7 — formal email. Day 15 — phone call.
Bad debt provision: For receivables over 180 days, consider creating a provision.

GST for consultants and accounting professionals

Registration threshold: ₹20 lakh annual turnover (₹10 lakh in special category states).

SAC codes: Management consulting — 9983, Accounting/auditing — 9982, Tax consulting — 9982, Financial advisory — 9983.

GST rate: 18% for all professional services (CGST 9% + SGST 9% for intra-state, IGST 18% for inter-state).

Reverse Charge: If you are a CA/CS/CWA providing services to a company or firm, RCM may apply.

Export of services: Advisory to foreign clients is zero-rated. Issue invoice in foreign currency, maintain FIRC, and file LUT.

Common fee structures and how to invoice them

Monthly Retainers: Fixed fee for ongoing advisory. Invoice on the 1st of each month for that month's services.

Project-based Fees: One-time fee for a defined project. Invoice 50% upfront, 50% on delivery, or milestone-based.

Hourly Billing: Common for advisory and consulting. Maintain time sheets. Invoice monthly with detailed time entries.

Value-based Fees: Fee linked to outcome. Invoice upon achieving the agreed outcome with calculation clearly shown.

Reimbursements: Travel, accommodation, software subscriptions — pass through at cost or with a small markup.

The complete professional services invoice

Your credentials: Name, qualifications (CA/CS/MBA/etc.), firm name, registration numbers, address, phone, email, GSTIN.

Client details: Company name, address, contact person, and GSTIN. For individuals, PAN may be required.

Engagement reference: Quote the proposal number, engagement letter date, or project code.

Service period: 'Services rendered during March 1-31, 2026' or 'Project completed on March 15, 2026'.

Detailed service breakdown: 'GST return filing for 3 GSTINs', 'Preparation of financial statements'.

Professional fees subtotal: Sum of all service charges before GST.

Reimbursements: Listed separately with descriptions and amounts.

GST calculation: Show taxable value, SAC code, GST rate, and tax amount.

Total payable: In figures and words. Include due date and payment terms.

Payment details: Bank account, IFSC, UPI ID. For large firms, include payment link or portal details.

Special considerations for audit and assurance work

Statutory audit fees: Usually fixed annually. Invoice after audit completion and before AGM.

Internal audit fees: Often quarterly. Invoice at the end of each quarter with summary of work performed.

Tax audit fees: Linked to tax filing deadlines. Invoice after tax audit report (Form 3CD) is finalized.

Certification work: Net worth certificates, turnover certificates — invoice upon issuance of certificate.

Peer review compliance: If you are subject to peer review, ensure your invoicing system maintains documentation standards.

Managing client expectations and payments

Clear engagement letters: Define scope, fees, billing frequency, and payment terms before starting work.

Advance billing for new clients: For clients with no payment history, take 50-100% advance.

Regular billing for ongoing work: Monthly billing for retainers and long projects.

Payment follow-up protocol: Day 1 after due date — friendly reminder. Day 7 — formal email. Day 15 — phone call.

Bad debt provision: For receivables over 180 days, consider creating a provision.

Invoicing for consultants, CAs, and accountants in India

Stop fighting with invoice templates.

GST for consultants and accounting professionals

Common fee structures and how to invoice them

The complete professional services invoice

Special considerations for audit and assurance work

Managing client expectations and payments

Keep reading

Legal invoicing for lawyers and law firms in India

What is an invoice? A complete guide for Indian businesses

Invoicing for consultants, CAs, and accountants in India

Stop fighting with invoice templates.

GST for consultants and accounting professionals

Common fee structures and how to invoice them

The complete professional services invoice

Special considerations for audit and assurance work

Managing client expectations and payments

Keep reading

Legal invoicing for lawyers and law firms in India

What is an invoice? A complete guide for Indian businesses