If you are GST Registered, or if you are operating under your own TSL, you should be getting the full GST inclusive portion of the hire & service fee (less Mighway commission) and then passing on the GST to IRD through your GST return (if applicable). For example, if you are a local owner with a van hire for $1000 and $100 cleaning fee, you will receive $850 for the hire and $85 for the cleaning fee. If you are not GST registered , you will get those amounts less 15% GST, unless you are using your own TSL.

Read more about TSLs here: https://www.mighway.com/nz/en/owners/gst-tsl