How to code a vendor invoice with mixed GST lines in Sage 300

A mixed GST bill has some lines with GST and some without, such as taxable goods plus GST-free items. Each line needs its own GST code.

Before you start

• Sage 300 Accounts Payable
• Security authorisation for the screen
• Tax Services set up with tax authorities, classes and groups

The Sage 300 way

Where to find it: Accounts Payable > A/P Invoice Entry > Taxes tab

1. Set up tax authorities, tax classes and a tax group in Tax Services.
2. Put the tax group on the vendor. The invoice picks it up.
3. Pick the tax entry method: Calculate (Sage works it out, with Tax Included Yes or No), Distribute or Enter (you type tax amounts).
4. On the Taxes tab click Distribute Taxes to allocate tax to each detail. With Enter you can edit each distribution tax amount.
5. Distribute amounts net of tax if tax is calculated and not included; include tax if it is included in the total.

Limits in Sage 300

• Calculate overrides tax typed by hand.
• Mixed GST and GST-free lines need separate tax classes on the details.

Good to know in Sage 300

• Set Calculate as the default on the A/P Options Transactions tab.

Words Sage 300 uses

• Tax Services. The shared Sage 300 module that holds tax authorities, classes and rates. A/P reads taxes from it.

The Pulsify way

1. Forward the supplier's invoice to your Pulsify address or upload it. Pulsify reads every line and finds the vendor in Sage 300.
2. Pulsify works out the GST rate for each line from what is printed and picks the matching tax class and tax authority in Sage 300.
3. Check any line where the invoice is unclear. Change the tax class and tax authority and approve.
4. The A/P invoice is created in Sage 300 with the GST on each line.

Pulsify connects to Sage 300. We set up the connection for you.

What Pulsify does not do here

• If the invoice does not show GST by line, Pulsify uses past bills for that vendor. Check those lines yourself.

Common mistakes

• Typing tax by hand while the method is on Calculate, which overrides it.
• Distributing amounts that include tax when tax is calculated and not included.

More help

• How to code an AP bill with mixed GST lines in Acumatica
• How to code a purchase invoice with mixed GST lines in Business Central
• How to code a purchase invoice with mixed VAT rates in Sage 200
• How to enter a vendor invoice with line items in Sage 300
• How to check GST coding on vendor invoice records in Sage 300 before you lodge your BAS
• How to code one A/P invoice to several GL account codes in Sage 300
• All Sage 300 how-to guides
• Pulsify setup guides

Sources

Last checked 2026-10-19. Confidence: partial.

• cdn.na.sage.com/docs/en/customer/300erp/2023/open/Sage300_AccountsPayable_UserGuide.pdf
• cdn.na.sage.com/docs/en/customer/300erp/2023/open/Sage300_AustraliaTaxReports_UserGuide.pdf