Often neglected, the local and unique sequential numbers for your invoices relative to operations abroad is a must. Italian authorities recently showed how inflexible they are on the issue.
A taxpayer intended to adopt an electronic invoice numbering system, which avoids showing customers and collaborators information about the total number of invoices issued. In order to guarantee the uniqueness and progressiveness of the numbers, that taxpayer had chosen to insert within the electronic invoice number the day of issue (e.g. 20200601) followed by a daily partial code in hexadecimal format (e.g. 000A).
The taxpayers asked the Italian tax authorities whether the daily partial numbering can be considered sequential even if it contains hexadecimal digits and if, with the changeover to the next day, the jump in the numbering of the daily partial code can be considered valid (by way of example, it is possible to change directly from invoice no. 20200601001F to invoice no. 202006020000).