1. Indian GST Invoice Compliance (GSTIN & HSN/SAC Codes)
Under Indian Goods and Services Tax (GST) law, registered businesses issuing tax invoices must include specific mandatory fields:
GSTIN / Tax ID Format
15-digit GST Identification Number (GSTIN) for both supplier and recipient (e.g. 07AAAAA0000A1Z5).
HSN / SAC Code Classification
Services use 6-digit SAC codes (e.g., 998311 for IT consultancy, 998314 for web design).
CGST + SGST vs IGST
Intra-state sales split tax equally into CGST & SGST. Inter-state sales apply full IGST rates (18%).
Section 50 Late Interest Rate
Delayed GST tax liability payments accrue a mandatory statutory interest rate of 18% per annum under Section 50.
2. US Client Invoicing (W-8BEN Forms & EIN/SSN)
When billing United States business clients from outside the US, US tax law requires non-US freelancers to submit a completed Form W-8BEN (Certificate of Foreign Status) to exempt income from 30% US backup withholding tax.
US-based contractors must provide their Employer Identification Number (EIN) or Social Security Number (SSN) via Form W-9.
3. European Union B2B Reverse Charge VAT
For cross-border B2B invoicing within the European Union or to EU clients, include the client's valid VIES VAT number and add the notice: "VAT Reverse Charge Applies — Customer to account for VAT under Article 196 of EU Council Directive 2006/112/EC".