Invoicing Setup

Setting the Starting Number

WHMCS allows you to set the next invoice number that it will generate. This is useful for if you want to start invoicing at a number other than 1 or start invoices for a new year from a new number. You do this as follows:

• Go to the Invoices tab at Configuration () > System Settings > General Settings or, prior to WHMCS 8.0, Setup > General Settings.
• Enter the next number to assign in Invoice Starting #.
• Click Save.

The value will then disappear from the field but the system will assign that number to the next invoice.

Automatic Invoice Generation

WHMCS automatically generates invoices for recurring products and services in advance of the due date.

You can configure exactly how far in advance to generate invoices using Invoice Generation in the Billing Settings section at Configuration () > System Settings > Automation Settings or, prior to WHMCS 8.0, Setup > Automation Settings.

• By default, this is 14 days.
• Click Advanced Settings for this setting to configure the number of days in advance to generate invoices on a per billing cycle basis.

The cron job performs the generation each day, so it's important to configure Cron Tasks.

Manual Invoice Generation

When creating an invoice manually, the due date defaults to the same number of days in the future as you allow for automatic invoice generation. You can configure this via Invoice Generation in the Billing Settings section at Configuration () > System Settings > Automation Settings or, prior to WHMCS 8.0, Setup > Automation Settings.

You can customize the due date via the Options tab when managing an invoice.

Invoice Reminders & Notices

WHMCS allows you to send:

• A maxmimum of one reminder prior to the invoice reaching the due date.
• Up to three overdue reminders once the invoice has passed the due date.

You can configure when you would like these notices go out in the Billing Settings section at Configuration () > System Settings > Automation Settings or, prior to WHMCS 8.0, Setup > Automation Settings.

Group Similar Line Items

You can enable this option in the Invoices tab at Configuration () > System Settings > General Settings or, prior to WHMCS 8.0, Setup > General Settings, the system will automatically combine any identical line items into one summarized quantity format. For example:

Monthly Lease $15.95
Monthly Lease $15.95
Monthly Lease $15.95

becomes

3 x Monthly Lease @ $15.95 $47.85

Only the client (printable) invoice uses this format. The Admin Area invoice will still display each item on an individual line.

Automatic Grouping of Items

WHMCS automatically groups products, services, addons and domains into a single invoice if they are due on the same date with the same payment method and the same person.

By doing this, it means the customer only receives a single invoice and only needs to make a single payment. This, then, reduces your transaction fees.

If you have a client for whom you do not wish this grouping to occur, you can disable it with Separate Invoices either in a clients profile or in client groups.

Continuous Invoice Generation

Continuous Invoice Generation refers to whether the system creates invoices for unpaid items. For example:

Consider a hosting account for which the customer pays monthly. The user places their order in January. They receive an invoice and they pay their invoice. In the following month, the user gets their next invoice and they pay that. Then, in March, the user receives their invoice but they don't pay it because they no longer wish to use the account or simply because they miss the emails about it. If you have disabled continuous invoice generation, the user would not receive any further invoices until they paid the March invoice. However, if you enable continuous invoicing, the user would receive invoices every month until termination, regardless of whether they paid for the item.

When you enable Continuous Invoice Generation, any product that is Active or Suspended will continue to generate invoices regardless of the status of its previous invoice(s). Pending, Completed, Cancelled, or Terminated services will not generate invoices.

Enabling Continuous Invoicing

To enable this feature, go to the Invoices tab Configuration () > System Settings > General Settings or, prior to WHMCS 8.0, Setup > General Settings, and check the checkbox next to this setting. After enabling this option, if there are users who are due invoices for months that you haven't yet invoiced, the system will generate one invoice on each cron run for the user for the following days after enabling this.

Proforma Invoicing/Sequential Invoice Numbering

This feature is primarily for EU-based companies where, for accounting reasons, it is sometimes necessary to ensure paid invoice numbers are sequential. Anyone can use this feature in WHMCS regardless of location.

Enabling Sequential Invoice Numbering

Configuring Sequential Invoice Numbering

To enable this feature:

1. Go to Configuration () > System Settings > Tax Configuration or, prior to WHMCS 8.0, Setup > Payments > Tax Configuration.
2. In the General Settings tab, enable Tax Support.
3. In the VAT Settings tab:
   1. Enable Proforma Invoicing/Sequential Paid Invoice Numbering.
   2. For Sequential Invoice Number Format, specify the format you want to use for numbering. You can also include letters (for example, include your company's initials and the year to differentiate invoices for each year to create WHMCS2007-{NUMBER}). WHMCS replaces {NUMBER} placeholder with that invoice's number.
   3. Update the value for Next Paid Invoice Number. This allows you to set the next number to assign to an invoice.
      • Each time a customer pays an invoice, the number increases by 1.
      • You may want to alter the number here if, for example, you remove an invoice or at the beginning of a new year, to start at 1 again.
4. If desired, update the value for Auto Reset Numbering. This determines when WHMCS will automatically reset the Next Paid Invoice Number to use for newly-paid invoices. You can set this to Never, Monthly, or Annually.
5. If desired, enable Set Invoice Date on Payment to have WHMCS change the due date of an invoice to the payment date.

Sequential invoice numbering is now enabled. Each time a customer pays an invoice, the system will apply the next number in the sequence.

Proforma Invoicing

Generally, you will use the sequential numbering in conjunction with proforma invoicing. Invoices will display Proforma invoice while in unpaid status and Invoice once a customer pays. You can enable this in the Invoices tab at Configuration () > System Settings > General Settings or, prior to WHMCS 8.0, Setup > General Settings.

Custom Invoice Numbering Format

WHMCS automatically assigns a numerical identifier, or invoice number, to each invoice that it generates.

The invoice number can be customised in a variety of different ways using text or numerical sequences to meet your accounting requirements. Here are some examples:

• ABC-123
• 01-01-2020~456
• IND/789
• ANYTEXT-2020-123

For detailed instructions on how to configure these custom invoice number formats, see the help article on Configuring a Custom Invoice Number Format.