CRM with Invoicing & Billing — GST Quote-to-Cash Built Into One System

Why bolted-on invoicing breaks a CRM (and how a native build fixes it)

Most CRMs stop at the quotation. The moment the deal is won, the sales team switches to Tally to raise the tax invoice, opens the NIC portal for the e-way bill, logs into a Razorpay dashboard to send the payment link, and then updates the CRM again — sometimes. Three days later nobody knows which invoices are paid, which are overdue, and which are stuck in dispute. Accounts and sales run parallel spreadsheets. The party ledger in Tally shows one balance, the CRM shows another, and the founder trusts neither.

A CRM with invoicing and billing built in removes the switching entirely. The same record that held the enquiry, quotation, and PO becomes the invoice. GST is calculated on the quotation line items. The e-invoice IRN and QR code are generated the moment the invoice is saved. The e-way bill is triggered when dispatch is confirmed. The payment link goes out on WhatsApp the same minute the invoice is printed. When the money lands, the party ledger auto-updates and the sales team sees the "Paid" tag on the same deal card they opened four months ago. One dashboard. One database. No re-entry.

Modules we build into a CRM with invoicing and billing

Every invoicing CRM ships with a party master, item master with HSN and SAC codes, GST rate library, and multi-GSTIN handling out of the box. On top of that we layer the modules the accounts team actually opens every morning — proforma invoice, tax invoice (B2B and B2C), bill of supply for composition dealers, delivery challan and dispatch note, credit note and debit note with reason codes, and recurring invoice schedules for retainer and subscription clients.

The billing engine handles GST slabs (0, 5, 12, 18, 28 per cent), reverse charge, TCS on scrap and MRP goods, TDS deduction on payments received, place-of-supply logic for intra-state versus inter-state, SEZ zero-rated invoices, and export invoices under LUT or bond with USD or EUR line pricing. e-invoicing is native — IRN and QR code are generated through the official IRP API the moment the invoice is saved, with retry logic if the portal is down. e-way bill runs the same way: auto-created on dispatch, cancelled on return, extended on transit delay, all without opening the NIC portal manually.

Payment collection is built in — Razorpay, PayU, Cashfree, and Stripe payment links go out on WhatsApp, SMS, and email the same second the invoice is printed. Aging buckets (0-30, 31-60, 61-90, 90+ days) drive an auto-reminder cadence so nobody has to manually chase. Bank statement upload reconciles UTR against invoice number and clears the ledger. The owner opens one dashboard every morning and sees invoices raised today, IRN generation failures, e-way bills expiring, payment links sent, collections received, and outstanding by party and by age.

• ›GST invoicing — B2B, B2C, bill of supply, credit note, debit note
• ›e-invoicing IRN and QR-code generation via IRP with retry logic
• ›e-way bill auto-create, cancel, and extend through NIC portal API
• ›Recurring and retainer invoice schedules with auto-generation
• ›Razorpay, PayU, Cashfree, Stripe payment-link and webhook sync
• ›Aging buckets 0-30, 31-60, 61-90, 90+ with auto-reminder cadence
• ›Bank statement upload with UTR-to-invoice auto-reconciliation
• ›Two-way Tally Prime and Tally ERP 9 sync — parties, items, ledgers

How we deliver a CRM with invoicing and billing project

Every engagement starts with a scoping call — 60 to 90 minutes on Zoom or in person at your office. We map your current invoicing flow (what tools you use, how many invoices per month, which GSTINs, which gateways, which Tally version, which WhatsApp Business Service Provider) and leave with a full workflow diagram. Within a week you receive a written blueprint with module list, screen wireframes, integration list, and a fixed-price, fixed-timeline quotation. No T&M billing. No hidden change fees.

Build runs from our Ahmedabad office over 10 to 16 weeks depending on integration surface. Every fortnight there is a Zoom demo of what shipped that sprint — real invoices, real IRNs, real payment links, on your test data. Historical data (party master, item master, opening ledger balances, open invoices, unpaid outstanding) is migrated from Tally, Zoho Books, or your current CRM as part of the fixed price. Go-live is staged one module at a time — proforma first, tax invoice next, then e-way bill, then payment gateway, then Tally sync — so the accounts team has time to breathe. Post go-live we stay on a fixed-fee monthly retainer for support and enhancements, and you own the source code, database, and deployment accounts from day one.

Tech stack and integrations the CRM ships with

Backend: Laravel (PHP 8.2) or Node.js with Express. Database: MySQL with strict tax-audit-safe schemas. Frontend: Next.js with React and Tailwind. Integrations shipped as standard: official IRP e-invoicing API, NIC e-way bill API, Tally Prime and Tally ERP 9 (official connector or middleware bridge), Razorpay, PayU, Cashfree, Stripe, WhatsApp Business API (Meta Cloud or Gupshup or AiSensy), and Gmail or SMTP for invoice email. Hosting: AWS Mumbai by default, or your existing DigitalOcean, Hetzner, or on-prem server. Every deployment is containerised, backed up nightly, and monitored 24x7 on the retainer.