--- title: "Digital Signature on Invoices: DSC, Scanned Sign, and E-Invoice IRP" description: "Digital signature on invoices in India: DSC vs scanned signature legality, IT Act provisions, and how IRP signing works." canonical_url: "https://billbabu.com/blog/digital-signature-invoices-india" markdown_url: "https://billbabu.com/blog/digital-signature-invoices-india.md" type: "blog-post" language: "en-IN" published: "2026-05-16" last_updated: "2026-10-08" author: "BillBabu Team" category: "Invoicing" tags: ["digital signature", "dsc", "e-invoice", "irp", "it act"] site: "BillBabu (https://billbabu.com)" --- # Digital Signature on Invoices: DSC, Scanned Sign, and E-Invoice IRP By BillBabu Team · Published 16 May 2026 · Updated 8 October 2026 · Category: Invoicing Digital signature on invoices in India: DSC vs scanned signature legality, IT Act provisions, and how IRP signing works. ## IT Act and Legal Validity Section 5 of the Information Technology Act, 2000 gives digital signatures the same legal status as physical signatures on Indian documents. A Class 2 or Class 3 Digital Signature Certificate (DSC) issued by a licensed Certifying Authority like eMudhra, Sify, or NSDL is required to legally sign electronic documents. GST law specifically requires invoices to be signed or digitally signed by the supplier under Rule 46. An unsigned invoice is technically invalid and can be rejected during scrutiny. ## DSC vs Scanned Signature Image A DSC is a cryptographic token tied to the signer's identity and timestamps the document at signing — it is non-repudiable. A scanned signature image pasted onto a PDF is technically a representation, not a digital signature, and offers no cryptographic proof. However, the GST council has clarified that a scanned signature on a properly numbered invoice is acceptable in practice, especially for small businesses without DSCs. Larger enterprises and listed companies should use DSC because audit teams and tax officers prefer it for evidentiary value. ## E-Invoice and IRP Signing Businesses with aggregate turnover above Rs. 5 crore must generate e-invoices through the Invoice Registration Portal (IRP). When an invoice is uploaded to the IRP, the portal digitally signs the JSON payload with its own private key and returns an IRN (Invoice Reference Number) and signed QR code. This IRP signature legally authenticates the invoice — the supplier's DSC is not separately needed once the IRP has signed it. The signed QR code must be printed on the physical invoice, and only an IRP-signed invoice is valid for ITC claim by the buyer. ## Practical Compliance Checklist For non-e-invoice businesses, either apply a DSC at the time of generating the PDF or include a clear signature image with the printed name and designation of the signatory. For e-invoice businesses, ensure your billing tool integrates with the IRP via API, the signed QR is printed on PDFs, and the IRN is communicated to the buyer. Keep DSC private keys secure — sharing the USB token across staff is a control weakness flagged in IT and statutory audits. ## How BillBabu Handles Signing BillBabu supports both modes: you can upload a scanned signature for the basic plan, or connect a DSC for legally binding cryptographic signing. For businesses crossing the e-invoice threshold, BillBabu integrates directly with the IRP, fetches the IRN and signed QR, and embeds them on the final PDF. This means you don't need to maintain separate software for e-invoicing as your turnover grows. **Built for Indian small businesses.** BillBabu is GST-compliant billing software that helps you create invoices, manage estimates, track payments and stay audit-ready — from your phone. [Learn more about BillBabu](https://billbabu.com/) or [download the app](https://play.google.com/store/apps/details?id=com.billbabu.app). ## Related guides - [EDF vs Shipping Bill vs SOFTEX: How Indian Exporters Declare Goods and Services in 2026](https://billbabu.com/blog/edf-vs-shipping-bill-vs-softex-export-declaration): Detailed comparison of EDF, Shipping Bill, and SOFTEX in 2026. Learn when each declaration applies, filing portals, deadlines, and foreign remittance closure. - [UPI for B2B Payments and Invoice Collections: Limits, Dynamic QR, and AutoPay for Indian Businesses](https://billbabu.com/blog/upi-for-b2b-payments-invoice-collections): How Indian businesses use UPI for B2B invoice collections: dynamic QR codes on GST invoices, ₹1 Lakh vs ₹5 Lakh limits, UPI AutoPay for recurring billing, and ERP reconciliation. - [Tax Invoice Cancellation Under GST: 24-Hour IRP Window and Credit Notes](https://billbabu.com/blog/tax-invoice-cancellation-gst-india): Tax invoice cancellation under GST: 24-hour IRP cancellation window, credit note approach beyond that, and GSTR-1 amendments. --- This is the Markdown version of https://billbabu.com/blog/digital-signature-invoices-india for AI assistants. Product summary and every page: https://billbabu.com/llms.txt