Invoicing Multiple Sales Order

In most cases we invoice one sales order, then in Sales order tab will reduce the Uninvoiced amount.

My client needs for me to invoice multiple sales order in 1 Invoice number? any idea this can be done?

Sorry, that is not possible. It will be impossible to track the invoiced amounts for the Orders.

Actually, it is not impossible. You just lose the ability to link sales orders to sales invoices. But nothing will stop you from invoicing line items from multiple sales orders on the same sales invoice. You have to create the sales invoice completely manually, though, rather than by copying the sales order to the sales invoice. Because this will totally throw off your Uninvoiced figures, it is definitely not recommended.

yes, i am aware i can do it manually.

But as you mentioned, if i do it manually, then definitely it will not update my invoiced/uninvoiced figures, which is what i wanted to prevent.