Invoice numbering
  • 30 Jan 2023
  • Contributors

Invoice numbering

For each estimate or document you issue, a number is generated that provides it with a unique identification. In this article, we will analyze the different ways this number may occur as well as the control you have over numbering, according to your needs.

1. Type-based invoice numbering

Every invoice type in Elorus defines a single serial numbering, provided that a specific sequence is not set at the time of issuing. For instance, the first “Invoice” document will receive the number #1, whereas the first “Receipt” will be also numbered with #1. For a more detailed explanation on document types, you may refer to our article.

2. Series-based numbering

Every series can be designated to one invoice type. When you add a new series on the application, you also define the invoice type to which it applies.
If you wish to add a series to more document types, all you need to do is ‘Add’ the series for each one of those types.

To add a new numbering series click on Settings -> Document Types select the desired document type you want to associate with the series and add the sequence

numbering sequence add

In order to apply a series when adding invoices, credit notes or estimates, you need to select one from the list next to the Number field.


Suppose that you created series “A” for both the “Invoice” and “Credit Invoice” document types. The first “Invoice” that you create will receive the numbering #A-1, the next one will receive numbering #A-2 etc. The first "Credit Invoice" will again receive #A-1 , #A-2 without affecting "Invoice" numbering sequence. This helps prevent gaps in numbering without the necessity of multiple names for each series.

3. Auto & manual document numbering

Elorus gives a new serial number to each document issued, automatically, starting with the number “1”. If you wish the numbering to start from a different number, you will have to manually type it on the first document you issue.

Then, Elorus will automate the serial numbering from that point forward, for every document you add of the same type.

If, for example, you wish to start numbering your Invoices from 40, on the “Add” (invoice) page, you have to unlock the numbering field by clicking on the “padlock” icon next to it and insert the number 40. Once the first document is saved, Elorus will assign number 41 to the next invoice you issue, 42 on the one after that and so on.


This way you may also manually alter every document’s number - either during creation or after it is saved, as long as it is in a draft state.

NOTE: In the case of non-EU organizations that follow an alphanumeric or a non-sequential numeric numbering you have to manually insert the desired number for sales and credit sales invoices.

4. Draft documents numbering

In Elorus you can choose whether your draft documents will receive a number or only after you have saved them as issued. From the application settings page you enable the "Auto numbering draft documents" option.

A problem, however, may occur when another document is being issued in the meantime.


The result will be that the draft, when converted into an official document, will have a later date (but smaller number) to the next- in line- official document. This, in some cases, may not be entirely correct. Another case scenario is, a draft be deleted resulting in serial numbering gaps.

Should these problems arise and you notice that you have to manually alter the numbering on several occasions, you can disable “auto numbering for draft documents”. In this way, every draft you save, will bear a “N/A” (Not Available) sign instead of a number. The document will receive proper numbering once you save it as issued.

Elorus - depending on the country of a registered organization - will provide you or not with the “force sequential numbering” and “numbering padding” settings. European Union (EU) member states are obliged to apply a unique sequential number identifying their invoices. The majority of non-EU member states may follow a unique alphanumeric numbering (e.g. Invoice ABC-123) or a unique non-sequential numeric numbering.

The numbering padding and the force sequential numbering features are not available in countries that may use an alphanumeric numbering or a non-sequential numbering.

5. Numbering padding

For all sales and credit sales invoices, you can determine your documents to get a specific length of digits as numbering, referred to as “numbering padding”. Practically, this means that your documents’ numbering can have a 3-digits figure, a 4-digits figure and so on, depending on what serves you best or the numbering your previous documentation used to get. Thus, you can continue using the same numbering format after you’ve moved on to Elorus invoicing or record older sales documents.

From the user’s menu choose Settings - > Application settings and set the numbering padding from 3 and up to 10 digits; for example 005 or 000005. If left blank, the numbering will start without padding.

6. Force sequential numbering

In case your organization is established in the EU, Elorus enables you to apply a mandatory “rule” regarding issued sales and credit sales documents numbering. This means that the system monitors whether the numbering follows a valid sequential order, in terms of date and numeral.

As a result, this feature prevents you from issuing documents that do not abide by the sequential numbering mandate. Note that, the "force sequential numbering" setting applies only to issued documents and does not affect those in a draft state.

For example, let’s assume that the last invoice was issued on 12/6/2015 and got the number 2. If you attempt to issue an invoice dated 12/5/15 and number 3, Elorus will not allow you to save it and will display a notification similar to the one below.


Please bear in mind that this rule only applies to official invoices and has no effect on drafts. If enabled, Auto-numbering of draft documents will be deactivated, thus drafts will NOT receive automatic numbering until they are converted into official documents.

To be able to utilize this feature, the numbering of already issued invoices must be valid up to present or the force sequential numbering setting be enabled upon creating your account in Elorus.

If your numbering is incorrect, you will not be able to activate the force sequential numbering rule and the message below will appear upon saving the changes in settings.


From the user’s menu choose Settings - > Application settings - > Enable Force sequential numbering.

Once enabled, Elorus will not allow you to edit issued documents.

In case you need to edit an invoice to alter other fields, besides invoice number and date, you will have to temporarily disable the force sequential numbering setting.

Finally, by pressing the “Sequential numbering” button found in the Application Settings menu, Elorus will run a check for errors in the sequence of documents, pinpoint them and provide you with suggestions to correct them.


NOTE: The force sequential numbering feature DOES NOT apply to estimates.

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