Purchasing Module — User Guide

1. Overview

The Purchasing module supports procure-to-pay on the expense side: purchase order → purchase invoice → Finance accounts payable. Suppliers and vendor payments are managed in Finance. Purchase requisitions exist as a lightweight register today.

Compared with Sales: same order/invoice status pattern, but partners are vendors, posting hits AP/expense/input VAT, and Purchasing adds a requisition entity.

Not in this module today: goods receipt, Inventory stock receipt, automatic warehouse posting, or automated requisition approval/convert-to-PO workflow.

2. Getting started

2.1 Prerequisites

1. Finance chart of accounts ready (typical posting defaults include AP, expense, and input VAT accounts).
2. Open fiscal year/periods.
3. Currencies configured.
4. Vendors created under Finance subsidiary vendors.
5. Users granted Purchasing permissions (and Finance journal post for invoice posting).

2.2 Main navigation

3. Suppliers

Suppliers are not owned by Purchasing. They are Finance partner sub-ledgers with partner type Vendor.

How to maintain: open Suppliers from the Purchasing menu (goes to Finance) or Finance → Subsidiary ledger — vendors.

When creating a purchase order or invoice, select the vendor from the partner list filtered to Vendor type.

4. Purchase requisitions

The requisition screen is a lightweight register.

Current limits:

• No line items, vendor, dates, or amounts on the entity
• No submit / approve / reject workflow methods
• No convert-to-purchase-order action in the API

Use requisitions as an organizational checklist if needed, then create the formal purchase order under Purchase orders.

5. Purchase orders

5.1 Header fields

There is no formal foreign key from order to requisition in the current model.

5.2 Lines

Line number, description, quantity, unit price, line total (quantity × price), optional expense account.

5.3 Statuses

5.4 Actions

Convert defaults: invoice number often PI-{OrderNumber} if not supplied; due date typically invoice date + 30 days; copies vendor, period, currency, rate, notes, lines, and tax.

6. Purchase invoices

6.1 Header fields

6.2 Lines

Same shape as order lines. Optional expense account per line overrides the default expense account when posting.

6.3 Statuses

6.4 Create paths

1. From order — Convert confirmed purchase order.
2. Standalone — Create invoice directly (optional order/requisition ids on the DTO).

6.5 Actions

6.6 Tax and amounts

Tax amount is maintained on the invoice header. On post, if tax is greater than zero, Finance debits the input VAT account. Total should equal subtotal + tax. Finance validates amount consistency within a small tolerance.

7. Supplier payments

Payments are not entered in Purchasing. Use Finance payment vouchers:

1. Open Supplier payments from Purchasing (redirects to Finance payment vouchers) or Finance directly.
2. Create a Payment for the vendor and treasury account.
3. Allocate to the posted purchase invoice open item.
4. Invoice paid/open amounts and status update via Finance allocation.

Unposting a payment allocation reverts the invoice payment amounts.

8. Overview screen

/purchasing/overview provides a purchasing overview for navigation and summary presentation. Treat operational truth as the live Purchase orders, Incoming invoices, and Requisitions lists plus Finance vendor/payment screens.

9. Permissions summary

Permission group: Purchasing.

Posting also requires Finance ability to post journal entries. Convert needs both order update and invoice create rights. Ensure roles that use Incoming invoices have Invoices permissions, not only Requisitions/Orders.

10. Integration with Finance

Default posting accounts are configured in Finance posting services (AP, expense, input VAT), with optional overrides from vendor GL account or invoice line expense account.

Appendix A — Quick procedures

A.1 Order to pay

1. Ensure vendor exists in Finance.
2. Create purchase order → Confirm.
3. Convert to invoice.
4. Post the invoice.
5. Create Finance payment and allocate to the invoice until Paid.

A.2 Standalone vendor invoice

1. Create Draft purchase invoice with lines, tax, and totals.
2. Post.
3. Pay via Finance payment allocations.

A.3 Correct a posted invoice before payment

1. Ensure PaidAmount is still zero.
2. Unpost → Draft.
3. Edit and post again, or cancel the draft if abandoning.

A.4 Use a requisition as a tracker

1. Create a requisition with a clear number.
2. Update status text per your internal process.
3. Create the purchase order separately when ready to buy.

Appendix B — Operating notes

Appendix C — Document control

This guide describes functional capabilities of the Purchasing module as implemented in the Vertex ERP codebase. UI labels may appear in English or Arabic depending on language settings.