TaxTMI 
TaxTMI 
Hello, one of my clients has supplied inverters & batteries along with installation and testing of the same on site to a government department. The tender required us to quote one single price for inverter and batteries together while one single price for services of installation, testing, freight etc. My query is can we mention 'inverter' as line item instead of inverter & batteries and charge 18% on complete invoice as composite supply?
Invoicing for supply to government department
03 Jun 2025 
4 Replies 
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Composite supply classification affects GST treatment when bundled goods and services are invoiced as a single line under tender terms.
Whether the supply of inverters, batteries and associated on-site services can be invoiced and taxed as a single composite supply depends on how the tender and purchase order characterise bundled goods and the applicable tax rates of constituent elements; the PO treated the battery as inseparable part of the inverter and may reject invoices that split the items, creating a tension between contractual billing requirements and statutory tax allocation for items with differing rates. (AI Summary)
Whether the supply of inverters, batteries and associated on-site services can be invoiced and taxed as a single composite supply depends on how the tender and purchase order characterise bundled goods and the applicable tax rates of constituent elements; the PO treated the battery as inseparable part of the inverter and may reject invoices that split the items, creating a tension between contractual billing requirements and statutory tax allocation for items with differing rates. (AI Summary)