General rules for invoice numbering
There are a few general rules that apply to invoice numbering:
- Invoice numbers are unique. Two different invoices cannot have the same number.
- The maximum recommended length of an invoice number is 10 characters. Invoice numbers can be used as variable or specific symbols. Banks might not accept symbols that are longer than that.
- You can choose the invoice number sequence format you want, but you should stick to it.
- Invoice number sequences should be continuous. There should be no gaps within them.
Invoice number sequence setting
You can set invoice number sequences in one of the following ways:
- During individual invoice generation
- During bulk invoice generation
Invoice number sequences are usually changed at the beginning of a new year. You might want to change, for example, the first four digits of the sequence from 2021to 2022.
During individual invoice generation
In the Individual invoice generation form (Client card / Invoicing / Issue invoice), there is an editable field named Invoice number. If you want to change the invoice number sequence for a given invoice group, change the preset value in this field.
During bulk invoice generation
In the Bulk invoice generation form (Invoicing / Invoices / Invoices –> Particular invoice group –> Generate new invoices for the month … for …), there is an editable field named Opening invoice number. If you want to change the invoice number sequence for the selected invoice group, change the preset value in this field. Enter a number that will be used for the first generated invoice.
Automatic invoice numbering
ISPadmin numbers invoices automatically. If you set an invoice number sequence correctly, the system will make your work in the future much easier. It is important, however, to understand how the automatic invoice numbering feature works.
Let us have a look at a specific example:
Beginning of the year 2022. Last year, an invoice number sequence starting with 202100001 was used for a given invoice group. Now you want to change the sequence. You decide to issue an individual invoice to make that happen. In the process, you will have to change the preset value.
- In 2021, the last number used was, for example, 202112134.
- The system automatically assigns a higher number (+1) to a newly generated invoice: 202112135.
- You want to use a different number, though: 202200001.
- Enter the number into the Invoice number field.
- Issue the invoice.
- The system will continue using the newly set invoice number sequence.
The system automatically provides you with new invoice numbers. They are calculated as follows:
- The system takes the highest number used in a given invoice group.
- It adds 1 to that number.
If the highest number used in the invoice group is 202112134, the system will suggest 202112135. If the highest number used in the invoice group is 202200001, the system will suggest 202200002 .
A new invoice number sequence for a particular invoice group must always be higher that all the previous sequences. If the sequence were lower, the system would still automatically suggest a value from the highest sequence because it works according to the rule highest number in the invoice group + 1.
Let us have a look at one more example:
- The highest number used in a particular invoice group is 202112134.
- In 2022, you decide to use an invoice number sequence starting with
- You enter 100000001 into the Invoice number field.
- You expect that the next invoice will be assigned number 100000002.
- However, the system suggests a different number instead: 202112135.
The number 100000001 is not the highest number in the invoice group. The highest number is 202112134!
Invoice number check during individual invoice generation
- An additional invoice number check was added to the system.
- If the number is not in accordance with the rule highest number in the invoice group + 1, a message appears during the save process that informs the user of the fact.
- The user can choose whether they want to continue or not. If the user confirms that they want to continue, the invoice with a given number is issued. If not, they can go back to the form.
- There is the Load button next to the field for entering an invoice number. Using this button, you can have the system retrieve the number that is in accordance with the rule.
New invoice group, proforma invoices and numbering
- If you create a new invoice group in which you want to primarily issue proforma invoices, it is necessary to set up an invoice number sequence for final invoices that are generated from proforma invoices.
- If you do not set up the sequence manually, it will lead to numbering issues!
- You can set up a sequence for final invoices by issuing a final invoice within a given invoice group.
- If you want, for example, a sequence beginning with 2022100001, you first need to issue a final invoice with number 2021100001 within a given invoice group. Only then can you start issuing proforma invoices. The system automatically numbers generated final invoices according to the above-mentioned rule.