How can i remove the nz dollar total on the invoice when its for an australian client so only needs to show australian dollar figures?

Hello there, Matt106. 

We can change the currency by changing the settings. I'll show you how: 

1. Log in to QuickBooks.
2. Click the Gear icon at the upper-right corner.
3. Select Account and settings.
4. From the Advanced menu, scroll down to select Currency. 
5. Choose and select the currency under the Home Currency drop-down.
6. Click Save and then Done. 

Changes will be made to future transactions. For the invoices that are saved prior to the change, the currency symbol are changed but the amount stays as is. 

Feel free to get back to me if you need anything else. You take care always!

@Matt106 

If your company is located in New Zealand, your default home currency should be NZD.

https://quickbooks.grsm.io/Asia-Pacific

You have to turn the multi currency feature on, create a AUD bank account, and create a customer profile with AUD to send a AUD invoice to your client.

Another option, utilize this payment service to deal with multi currency transactions. You may release invoice and get paid in NZD, and your client will pay it in AUD.

https://veem.grsm.io/veems