Have you tried a POA (payment on account) as a way to prepay?

Thanks for your response, yes  POA (payment on account) is working but Client wants know why it is not allowed for Advance invoice.

Hello @teckrantk 

The reason is advance invoices can be matched with a final debit invoice on Manual Supplier Invoice. Matching window is automatically filtering advance invoices from debit invoice supplier. Since one-time supplier invoice is created against temporary supplier, system is preventing users matching wrongly.

Hope this helps

@gumabs  Many thanks for your explanation.