In South Asian and MENA retail, Cash on Delivery is not a fringe option — it is often the majority of order volume. But out of the box, ERPNext treats COD as an afterthought: you can flag a Sales Order or Sales Invoice as "unpaid" and hope the courier collects, yet there is no native OTP verification to filter fake orders, no configurable COD surcharge, no per-customer or per-region collection limits, and no structured way to track which orders a courier has picked up, delivered, collected cash on, and remitted back to you. Finance teams end up reconciling courier remittance sheets against invoices by hand in spreadsheets, RTO (return-to-origin) losses go untracked, and the gap between "delivered" and "cash actually received" stays invisible in the general ledger.

ECOSIRE builds a proper Frappe app — a versioned module installed on your bench, not a pile of customizations — that makes COD a controlled, auditable payment method inside ERPNext. We add a COD checkout/order path with new DocTypes such as COD Order, COD Settings, and Courier Remittance, wired into the standard Sales Order and Sales Invoice lifecycle. Phone/OTP verification runs through a whitelisted server method (@frappe.whitelist()) that issues and validates a one-time code via your SMS/WhatsApp gateway before an order is confirmed, cutting fake and duplicate COD orders. COD surcharge and collection limits live in COD Settings and are applied via hooks.py doc events (before_save / validate / on_submit) so the fee lands as a real line item or charge and limits are enforced server-side — never bypassable from the client.

On the fulfilment and finance side, the app tracks the full cash journey: courier assignment, pickup, delivery status, cash collected, and remittance batches. A Courier Remittance DocType reconciles collected amounts against the originating invoices and generates the matching Payment Entry records against the correct receivable accounts, so your GL reflects cash received the moment a courier settles — with COD fees, RTO, and short-payments accounted for rather than silently lost. Scheduler events (scheduler_events in hooks.py) can auto-expire stale OTPs, flag overdue remittances, and poll courier status where an API is available. Client Scripts surface COD status and OTP actions directly on the ERPNext form, everything respects role-based permissions and role profiles, and the whitelisted endpoints are consumable from your storefront or the Frappe REST API for a headless checkout.

Because this is build-to-order, nothing ships as a blind download. We start with a short scoping call to confirm your couriers, remittance workflow, fee rules, SMS/WhatsApp provider, and whether you are on Frappe/ERPNext v15 or v16. We then build and unit-test the app against your requirements, deploy it to a staging site for UAT, and only cut over to production once you have signed off — with a documented rollback path. Typical delivery is one working week from confirmed scope, and you receive the full git repository so the code is yours to keep, audit, and extend.