You can enter a "bill" for the zero-cost service with just GST - it's a work around because QBO doesn't let you enter a tax-only entry.
Line 1 - Repairs and maintenance (or whatever GL account you would use) Amount 0.01 - Tax GST 5%
Line 2 - Repairs and maintenance (same as previous line) Amount (0.01) - Tax Out of Scope
Enter the actual GST amount in the Tax/GST field
**Entering the 0.01 and the -0.01 will cancel each other out (so no actual change to your GL of Repairs) but it will give you the option to enter an amount of GST.**
Save.
Hope this helps.
