The system will not allow a duplicated invoice number. If you enter a Duplicated invoice number, the system will advise the original Purchase Order number that the Invoice has been used against. If any additional characters, full stop, brackets etc has been used, this isn't a true duplication. Provide us with the purchaser order number.
📌If you are raising the Invoice as a self-managed or adhoc supplier then you need to contact us.
If you are asking on behalf of your supplier, then you need to ask your supplier to contact us directly.