Sorry again – but once I’m started you won’t hear from me again! I charge vat of 23% on top of my fee. How do I make sure the vat is an extra and not deducted from my rate

Sure that’s no problem. 
Like I mentioned just play around with it. All invoices are previewed on the right, we have an advanced option to include vat in the price. 
Here is a video I made for you. You can see me play around with the invoice, and delete it. 
Hope that helps.

Pete