How to Create an Invoice
Quick Summary
Create an invoice by selecting customer details, adding products or services, applying tax/discount settings, and saving the bill. This process keeps billing accurate and improves payment tracking.
What Is This Feature
The invoice creation feature generates a formal sales document for goods or services sold to a customer. It records quantity, rate, taxes, due amount, and payment terms in one place.
Why This Feature Is Important
Invoices are the core proof of sale. They help you collect payments, keep legal records, and feed data into accounting and reporting modules.
When To Use This Feature
- When a customer buys products or services
- When converting a quote/order to a final bill
- When recording credit sales to collect payment later
- When sending tax-compliant billing documents
Step-by-Step Flow
- Open Sales > Create Invoice.
- Select the customer (or add a new customer).
- Add product/service line items with quantity and price.
- Apply tax, discount, shipping, or extra charges if needed.
- Set invoice date, due date, and payment terms.
- Review totals, save invoice, and share (print/PDF/WhatsApp/email).
Fields Explanation
| Field | Purpose | Example |
|---|---|---|
| Invoice Number | Unique reference for tracking and audit. | INV-2026-0412 |
| Invoice Date | Date of billing entry. | 31-Mar-2026 |
| Customer | Buyer account linked to receivables. | ABC Traders |
| Item / Service | What is being billed. | Thermal Paper Roll |
| Qty x Rate | Calculates line subtotal. | 10 x 42.00 |
| Tax | Applicable tax rate per line or invoice. | GST 18% |
| Due Date | Expected payment deadline. | 15-Apr-2026 |
Optional Settings
- Round-off control for final amount
- Custom invoice template and logo
- Terms & conditions footer
- Auto-share after save
Underlying Concept (Accounting / Logic / Calculation)
On save, invoice posting typically updates Sales, Accounts Receivable, and Inventory/COGS (for stock items). Grand total follows:
Grand Total = Line Subtotal - Discount + Tax + Additional Charges
Interaction With Other Features
- Inventory: stock is reduced for billed items
- Orders: sales orders can be converted to invoice
- Accounting: receivables and tax ledgers update
- Reports: sales summary and customer statement update
Logical Behavior in Different Scenarios
Cash Sale
Invoice can be marked paid instantly and receivable closes immediately.
Credit Sale
Receivable stays open until payment entry is posted.
Out-of-Stock Item
System may block or warn depending on negative stock settings.
Common Mistakes
- Wrong tax selection for customer or item
- Skipping due date in credit invoices
- Editing quantity after confirming delivery without adjustment
- Using free-text item lines instead of mapped products
Troubleshooting
Invoice Not Saving
Check required fields: customer, item lines, invoice date, and tax setup.
Total Not Matching Expectation
Verify discount type (line or overall), tax mode (inclusive/exclusive), and rounding setting.
PDF/Print Layout Broken
Switch to default template and test logo size, custom footer, and paper settings.
FAQ Section
Yes, usually until accounting lock period or payment reconciliation rules restrict edits.
Open the saved invoice and use share options such as PDF, print, WhatsApp, or email.
Yes. Most systems calculate tax per line item based on each item’s tax rule.