Invoice sequential number

What would happen if my system do not allow me to do an invoice so I decide to do it manual? What to do regarding the sequential number of the invoices to reflect that I have one manual and not duplicate the number or have a gap?

Hi,
 

Please keep a record in your accounts as to why the invoice has been issued manually  . Thank you .

In that case which sequential number the manual invoice would have?

Why are you raising a manual invoice? Sequential means what it say, sequential. If you raise a manual invoice, it should follow the last invoice issued by you. So if the last invoice was 248 then your manual invoice will be 249. Remember, for VAT all your invoices must be recorded in your accounting software or spreadsheet, so that when the VAT return is submitted, it contains a digital record of each sale, so even where you raise a manual invoice outside of your normal accounting system, you still have to make a manual entry in your VAT account/VAT records so that the manual invoice feeds into your VAT return.

Hi,
 

Use a different ref to your electronic invoices to indicate it is a manual invoice  . Thank you.