Invoicing Overview

Invoicing is the core of Hisaabo. Every sale or purchase you make flows through an invoice. This page gives you a map of the invoicing system so you know which feature to reach for in each situation.

Invoice types

Hisaabo has two invoice types:

• Sale invoice — you are selling goods or services to a customer. Stock decreases when a sale invoice is created.
• Purchase invoice — you are buying goods or services from a supplier. Stock increases when a purchase invoice is created.

Document types

Within sale and purchase, Hisaabo supports multiple document types. Each has its own sequential number series:

Document Type	Use for	Number prefix (default)
Invoice	Standard tax invoice	INV
Quotation	Price quote before the order is confirmed	QTN
Proforma Invoice	Pre-delivery invoice for advance payment	PI
Delivery Challan	Proof of goods dispatched, no tax invoice yet	DC
Credit Note	Reducing the amount owed by the customer (sales return, price correction)	CN
Debit Note	Increasing the amount owed by the customer (additional charges)	CN (shares credit note prefix and counter)
Sales Return	Customer returning goods	CN (shares credit note prefix and counter)
Purchase Return	Returning goods to supplier	CN (shares credit note prefix and counter)

Tip

Change the default prefixes for each document type in Settings → Business Profile. You can also configure the starting number if you are migrating from another app.

Stock effects by document type

Not all document types affect stock. Here is how each type interacts with inventory:

Document Type	Stock effect
Invoice (sale)	Decrements stock
Invoice (purchase)	Increments stock
Delivery Challan	Decrements stock
Credit Note	Increments stock (returned items go back into inventory)
Sales Return	Increments stock (returned items go back into inventory)
Purchase Return	Decrements stock (items sent back to supplier)
Quotation	No stock effect
Proforma Invoice	No stock effect
Debit Note	No stock effect

How invoice numbers are assigned

Invoice numbers are assigned inside a PostgreSQL transaction using a SELECT FOR UPDATE lock on the business row. This guarantees that:

• No two invoices get the same number, even if two users create invoices at the same time
• Numbers are always sequential with no gaps (as long as you do not delete invoices)

The format is PREFIX-NNNNN, for example INV-00001. The counter pads to 5 digits by default.

How stock is updated

When you create a sale invoice, stock is decremented for every line item that references an item in your catalogue. When you create a purchase invoice, stock is incremented. This happens inside the same database transaction as the invoice creation, so stock and invoice totals are always consistent.

If you have an item with alternate units, the quantity is converted to the base unit before the stock update. For example, if you sell 2 boxes of 12 pcs, and the conversion factor is 12, the stock is decremented by 24 pcs.

If you have an item with variants (for example, a t-shirt in size M and colour Red), the variant’s stock is decremented rather than the parent item’s stock.

Editing an invoice’s line items reverses the original stock adjustment and applies the new one.

Invoice statuses

An invoice moves through the following statuses during its lifecycle:

Status	Meaning
draft	Created but not yet sent or confirmed. Can be freely edited.
unfulfilled	Goods have not yet been dispatched.
sent	Invoice has been sent to the party.
paid	Fully paid.
partial	Partially paid.
overdue	Past the due date with an unpaid balance.
cancelled	Cancelled or soft-deleted.

You can manually change the status of an invoice at any time. Statuses are also updated automatically when payments are recorded.

Note

Other document types have a subset of these statuses. Quotations, proformas, and delivery challans support draft, sent, and cancelled. Credit notes and debit notes support draft, sent, paid, and cancelled.

See Invoice Statuses for the full status workflow.

GST on invoices

Hisaabo automatically calculates CGST/SGST (intra-state) or IGST (inter-state) based on the 2-digit state codes stored on your business and the customer/supplier. You set the GST rate on each item (0%, 5%, 12%, 18%, or 28%) and Hisaabo applies the correct split on each invoice.

See GST on Invoices for full details.

PDF generation

Every invoice can be downloaded as a PDF in three formats: A4 portrait, A5 landscape, and 80mm thermal roll. The PDF includes your business logo, GSTIN, party details, line items with HSN codes, tax breakdown, and optionally your bank account details and a UPI QR code for easy payment.

See Invoice PDF for full details.

Document conversion

You can convert a document from one type to another — for example, converting a quotation to an invoice, or a proforma invoice to a tax invoice. The conversion creates a new document of the target type, copying all line items and party details from the original. The new document is linked to the source document via the Reference Document field.

Linked documents

You can link documents to each other using the Reference Document field. For example:

• A credit note references the original invoice it corrects
• A delivery challan references the sale order it fulfils
• A purchase return references the original purchase invoice

This linkage appears in the invoice detail view and in GSTR-1 reports (credit and debit notes show the original invoice number).

Next steps

• Create an Invoice — step-by-step walkthrough
• GST on Invoices — understanding CGST, SGST, and IGST
• Invoice PDF — downloading and sharing PDFs
• Invoice Statuses — the full status lifecycle