Purchase Invoices
Learn about Supplier Invoices in Marlin GTX trusted automotive software by Megabus.
Updated 12 October 2026
**Marlin GTX** enables the recording of supplier invoices, expenses and assets using the Purchases module.
The Purchases module can be accessed by selecting Main > Data Entry > Purchases from the menu bar.
Note
The Purchases module can also be used with Delivery Dockets to receive stock before invoicing.
See the Delivery Dockets help guide for further information.
Invoicing Purchases
Main > Data Entry > Purchases
Purchases can be invoiced to record supplier charges and bring products into stock.
By default, the Purchases module will open on the Supplier Tax Invoice screen.
Click on Supplier Tax Invoice in the New Transactions section on the left if required.
In the Enter Supplier Tax Invoice screen:
- Select the Supplier
- Enter the Supplier Invoice Number
- Select the Salesperson
- Select the Date for the transaction
- Enter the Total Invoice Amount
- Press Tab on the keyboard
- The GST amount will be automatically calculated
Use the Line Details list to add products:
- Click on the picker (magnifying glass) icon to select the product (or press F4)

Click on Use Catalogue Code or Use Product Codes at the top to switch between code types, if required
- Add to the Description, if required
- Enter the Quantity
- Click the Add button at the top to add a new line and repeat, if required
- Click Finalise (top of module) and confirm
- Enter a Payment Due Date, if required
The Total Invoice Amount will be added to your outstanding balance with the supplier.
Any products on the invoice will be brought into stock and can be sold as usual.
Note
By default, costs are shown as excluding GST, but the Show/Hide GST button

can be used to toggle between excluding and including GST.
Tip
Supplier contact details can also be viewed by clicking Show Supplier Details and closed by clicking Hide Supplier Details.
Tip
Entire purchase order details can be quickly added to supplier invoices by clicking on the down-arrow next to the Add button and selecting Import Purchase Order.
Non-Inventory Expenses
Main > Data Entry > Purchases
Non-inventory expenses or business assets can also be added to supplier invoices by selecting an Expense Code or Asset Code when selecting a product to add to the invoice details list.
Example
Select Telephone Landlines for a phone bill, or Plant and Equipment for equipment purchases.
Note
Expense and asset codes must be added as products before they can be selected. See Product Maintenance.
Pickers open picklists by clicking on the Magnifying Glass icon

Shortcut: F4
Add button

Shortcut: Insert
