Supplier bill export to Fortnox

Export supplier bills from Opter to Fortnox. For instructions, see below.

If both invoice and supplier bill export to Fortnox are being set up, we recommend first setting up the invoice export according to Invoice export to Fortnox, and then the supplier bill export.
Export invoices from Opter to Fortnox. For instructions, see Invoice export to Fortnox.
Importing payments from Fortnox to Opter. For instructions, see Payment import from Fortnox.

Every time you export supplier bills, Fortnox checks if there is anything to update in the supplier bills or hauliers/subcontractors. Fortnox only updates supplier bills that have not yet been recorded in Fortnox.

Supplier bill and account coding amounts are sent including VAT.

Settlement data sent from Opter to Fortnox

In Fortnox there is no support for presenting all the details that you might want to include on a transport statement, such as the amount per vehicle/driver and date, service and fuel surcharge. The graphic supplier bill with all the details is therefore created in Opter and sent to Fortnox as a PDF file, if the relevant setting is set. (For instructions, see below).

When an supplier bill export is made to Fortnox, Opter sends a summary of each unique coding combination. This means that Opter sends one supplier bill row per combination of ledger account and economic unit.

The following information is sent to Fortnox in the supplier bill export:

Supplier bill number.
Supplier bill date.
Due date of supplier bill.
Supplier bill account coding.
Name, address, country, two telephone numbers, fax number, website, bank account number, IBAN, BIC, bankgiro number, plusgiro number, VAT number, company ID number and default currency of the supplier/subcontractor. The default currency of the supplier/subcontractor is set to the same default currency as Opter.
The supplier bill as a PDF attachment, if the Include PDF-copy checkbox is selected. (For instructions, see below).

It is not possible to export economic units.

Conditions

Integration licence and invoicing licence

To be able to connect (integrate) Opter to Fortnox, you need an integration licence. You also need to have a software licence for invoicing in Fortnox. These licences (also called "programs" and "add-ons") can be ordered in the Fortnox program. Contact Fortnox if you need more information about your licences.

Payment imports require the software licences for invoicing and accounting in Fortnox.

Invoice export requires the software licence for invoicing in Fortnox.

Web browser

In order to export to Fortnox, it is important that you use a modern standard browser, such as Edge, Firefox or Chrome.

Standard currency

In order to export invoices and supplier bills to Fortnox and import payments from Fortnox to Opter, the default currency in Opter must be Swedish kronor (SEK).

If your Opter has a default currency other than XML, you will receive the error message The default currency has to be SEK to allow supplier bills to be exported to Fortnox. Current default currency is: {0} when you try to export supplier bills to Fortnox.

Do not change the default currency as that would cause major problems in the system. If you have a standard currency other than Swedish kronor, it is not possible to export invoices and supplier bills to Fortnox and import payments from Fortnox.

Currency codes

Fortnox only accepts three-letter currency codes, such as “DKK”, “SEK”, “GBP” and “EUR”.

Exchange rates

It is important to always have exactly the same exchange rates in Fortnox and Opter to avoid problems such as exchange rate losses, and payments that do not match the invoice in Opter exactly and are therefore registered as advances.

To always have the same exchange rates in Fortnox and Opter, proceed as follows:

In Fortnox under Invoicing > Currency, set Automatic exchange rates to “NO”.
Set exactly the same exchange rates in Fortnox and Opter. When updating an exchange rate, change the exchange rate at the same time in both Fortnox and Opter. In Opter, exchange rates are set under Economy > Currencies on the Currency rates tab.

Bank account number, clearing number

The haulier's/subcontractor's bank account number is sent to Fortnox in the settlement export. Opter retrieves the bank account number from the Bank account number field in the carrier/subcontractor register (on the Pricing and Billing tab). Please check that you have the correct bank account number in the field and that it is entered in the correct format.

If the bank account number belongs to a Swedish bank, the bank account number consists of a clearing number (four to five digits) and an account number.

Fortnox has one field for the clearing number and one for the account number, while Opter has one field (Bank account number) that can contain both the clearing number and the account number, or just the account number. As of version 2025.12.00, Opter can distinguish which digits are the clearing number and which are the account number, if you enter them in the correct format in the Bank account number field.

Proceed as follows:

If the bank account number belongs to a Swedish bank, enter the clearing number, followed by a comma or space, and then the account number. For example, if the clearing number is "83279" and the account number is "1466399999", type in one of the following ways in the field Bank account number:
- 83279,1466399999
- 83279, 1466399999
- 83279 1466399999
- 8327-9 1466399999
- 8327-9 146 639 9999
- 8327-9, 146 639 9999
Details

Opter understands which digits are the clearing number and which are the account number as long as the first comma or space is after the full clearing number. So, after the first comma or space, you can have as many commas or spaces as you like, for example to make the bank account number easier to read.
If it is not a Swedish bank account number, enter all the digits in a row in the field Bank account number. Opter then sends all the numbers to Fortnox as a bank account number (without a clearing number).

Accounts for accounts payable, input VAT and rounding

For Fortnox and Opter to work well together, make sure there are the same account number for accounts payable, input VAT and rounding in Opter and Fortnox. The default settings are as follows:

Account 2400 is the default for accounts payable in both Opter and Fortnox.
Account 2640 is the default for input VAT in Opter, but in Fortnox account 2641 is the default.
Account 3740 is the default for rounding in both Opter and Fortnox, and the account is called "Rounding" in Fortnox.

Supplier bills are called "supplier invoices" in Fortnox.

Step 1: Create a self-signed certificate

For instructions, see Invoice export to Fortnox.

If both invoice and supplier bill export to Fortnox are being set up, we recommend first setting up the invoice export according to Invoice export to Fortnox, and then the supplier bill export.

Step 2 (optional): Adding a service account

If you/you want to use a service account for settlement export, see Invoice export to Fortnox.

Step 3: Create a supplier bill export in Opter

Click on Economy > Supplier bills > Supplier bill export to create a new supplier bill export. The following fields must be filled in on the General tab:
- Name: for example “Fortnox”.
- Type: Fortnox.
- Encoding: ISO-8859-1.
(Leave the API token field empty. The field is not used).
Tick the checkbox Use service account if you want to use a service account for settlement export. How to add a service account is described in Invoice export to Fortnox.
Select the Include PDF-copy checkbox if the graphical supplier bill with all the information from Opter is to be sent to Fortnox as a PDF file.
Click on Save to save all changes.

Step 4: Add the supplier bill export to a supplier bill export group

Click on Economy > Supplier bills > Supplier bill export settings and select “Fortnox” (or the name you gave the supplier bill export) for the groups that should be able to generate an export to Fortnox. A new export group can also be created. Since all supplier bills are to be recorded in the accounts, you should select the export for all export groups.

Step 5: Export supplier bills to Fortnox

Supplier bill information can be exported from Opter when closing a supplier bill period, or subsequently when it is possible to export entire supplier bill periods but not individual supplier bills.

When exporting, a supplier bill is created in Fortnox with supplier bill lines that correspond to the account coding in Opter.

To export supplier bill periods retrospectively, proceed as follows:

In Opter, click on Economy > Supplier bills > Supplier bills.
Right-click on a supplier bill period and select Export.
Click on Export and send.

If you are not already logged in to Fortnox, a new window will open where you log in with your usual Fortnox username and password. If authentication is successful, the export will start.

The web window with the text “Close this window” can be closed at any time, it will not interfere with the supplier bill export.

At the bottom of the Supplier bill export window in Opter, a progress bar is displayed. When the supplier bill export has been completed, the entire progress bar is green. If the supplier bill export fails, the progress bar turns grey and there is a statement indicating that the export failed.

If not all supplier bills are exported during the first attempt, click on Export and send again. There will be no extra supplier bills if you export again. Each time an supplier bill is exported, Fortnox updates the supplier bill if it is not recorded in Fortnox.

Troubleshooting

If the transfer to Fortnox does not work, an error message is displayed. Error messages only appear if something goes wrong during export. Error messages are displayed in a popup window, and are not saved anywhere.

If a supplier bill cannot be exported in full, any remaining parts of the supplier bill are automatically deleted from Fortnox. The errors are usually due to one of the following:

The supplier’s or subcontractor's address is incorrect or missing (on the General tab in the relevant registry).
The Fortnox web service is currently down.

If the export to Fortnox does not work, it may be due to one of the following reasons:

If exports are done from several different computers, and they work on some computers but not on all of them, it is probably because the computer does not have a self-signed certificate. All computers that will be capable of exporting invoices and supplier bills to Fortnox must have a self-signed certificate to be authenticated. For instructions, see Invoice export to Fortnox.

The certificate expires after one year without notice. If a certificate has expired, you will receive the error message The user details were not accepted by the external system.
Your browser is too old or Internet Explorer opens by default. In order to export to Fortnox, it is important that you use a modern standard browser, such as Edge, Firefox or Chrome.
You do not have a licence. For more information, see Invoice export to Fortnox.
If your Opter has a default currency other than XML, you will receive the error message The default currency has to be SEK to allow supplier bills to be exported to Fortnox. Current default currency is: {0} when you try to export supplier bills to Fortnox. See Standard currency above.