If your business runs on ERPNext and lives on outstanding receivables, you already know where the native flow runs out of road. Standard ERPNext can email a Sales Invoice PDF and, with a payment gateway configured, expose a generic "Pay Now" button on the portal — but it has no first-class concept of a trackable, expiring, branded payment link per invoice. There is no partial or installment collection against a single link, no SMS or WhatsApp delivery channel, no structured reminder-and-dunning cadence, and no way to route different invoices to different gateways. Your AR team ends up chasing payments manually, pasting gateway URLs into ad-hoc emails, and reconciling bank hits by hand — slow, error-prone, and invisible in the ledger until someone keys in a Payment Entry.

Payment Links & Invoicing Pro closes that gap. ECOSIRE builds it as a proper Frappe app installed on your bench — a real module with its own DocTypes, not a pile of Customize Form tweaks. At its core is a Payment Link DocType that references the source Sales Invoice, carries a signed public token, an expiry datetime, an outstanding-vs-collected balance, and a status lifecycle (Draft, Sent, Partially Paid, Paid, Expired, Cancelled). A one-click action on the Sales Invoice — added via a client script button that calls a @frappe.whitelist() server method — generates the link and dispatches it. A public web page (a Frappe website route / portal page) renders your branding, the invoice summary, and a gateway checkout that accepts full or partial amounts.

Delivery is multi-channel and driven by hooks.py doc events and the scheduler. On submit or on demand, the app sends the link by email (Frappe's Email Queue), SMS (your configured SMS Settings / provider), and WhatsApp (via your WhatsApp Business API or provider of choice) using version-controlled Notification and Print Format templates. A scheduler event walks unpaid links on a cron/daily hook to fire reminder and dunning steps you define, and to expire stale links. When a customer pays, the gateway callback lands on a whitelisted webhook handler that validates the signature, writes a Payment Entry against the invoice, allocates the amount (supporting partials and installment plans), updates the link's collected balance and status, and closes the loop so the ledger is always current. Multi-gateway routing lets you send, say, card traffic to one provider and bank-transfer to another based on rules you specify. Role Profiles and DocType permissions keep AR clerks, finance managers and read-only auditors scoped correctly, and every send, view and payment is captured for audit.

Because this is build-to-order, nothing ships until we agree on scope. We start with a short scoping call, confirm your gateways, channels, reminder cadence, branding and ERPNext version (v15 or v16), then build the app against a staging copy of your site. You get UAT on staging, a rollback plan, and a documented install — typical delivery is 2–4 weeks from confirmed scope. There is no instant download; ECOSIRE writes, installs and supports the code, and hands over the git repository so you own what we build.