I want to show account numbers on Payment & Receipts
your supplier or customer to whom you are providing the payment/receipt voucher has no use of knowing what account you are posting your business transaction records to. so what is your use case?
If we want to use Payment for internal purpose only, is it possible or a kind of choice to show account numbers on it?
There is no such capability built into Manager. If you want to show account numbers, either for the bank account from which a payment is made or the account number to which the payment is posted, you will have to add a custom field for that purpose.
Any one out there, who have tried this?
please let me know
You are encouraged to try this yourself. Create a test business and add a custom field as advised by @Tut. You can share your trial results here and in case of difficulty show the edit and result screens so others can advise.