Final answer:
To create a partial invoice against an estimate in QuickBooks Online Simple Start, the new client needs to upgrade to QuickBooks Online Essentials or higher.
Step-by-step explanation:
To create a partial invoice against an estimate in QuickBooks Online Simple Start, the new client needs to upgrade to QuickBooks Online Essentials or higher. The feature of creating partial invoices is not available in QuickBooks Online Simple Start, so upgrading to a higher version is necessary.