By default, a split plan can email every invoice when the plan is created. You can change this so only the first invoice goes out right away. Each next invoice is emailed when the previous payment is due or paid, or a few days before its own due date.
Where to find it
Depositly → Settings → Notifications → Installment invoices → Email each invoice when it's next due
How to set it up
Go to Settings and scroll to Notifications.
Under Installment invoices, choose Email each invoice when it's next due.
Click Save.
Buyers can still pay any part early from their payment list.
For split orders you create yourself
When you create a split order manually, the invoices are sent as soon as you click Create. To send a later payment only when you're ready:
Create the split order with just the first payment.
When you're ready for the next one, open the order and click Add payment. Only that new invoice is sent.
You can also set a due date on each payment with Change due date. This moves the reminder, not the invoice itself.