Hi @Chriswxm76
You could show a deposit taken on the invoice but that's for information only.
There's no real need to mention any payment plan / arrangement on the invoice.
If the invoice is £1000 plus VAT (total = £1200) the debt is cleared once all £1200 is received.
Receive the instalments into QBO using Receive Payments - mark each against the invoice until cleared.
Hope this helps.