Many self-storage operators need extra information on their invoices to meet local regulations or customer procurement requirements. A French operator might need a SIREN number. A Spanish operator might need a passport or national ID number for private customers. A Belgian customer might require a purchase order reference.
Custom invoice fields let you define these fields once and have them appear automatically on every invoice. You configure the fields at the location level, assign values on the customer record and the data flows through to Stripe invoices without any manual work per invoice.
How custom invoice fields work
Each custom invoice field has three properties you define:
Field name - a label like "SIREN" or "Purchase Order Number". This name appears on invoices, in exports and across the Manager UI.
Field level - whether the field belongs to the customer (reused across all their bookings) or to a specific booking.
Customer type - whether the field applies to business customers, private customers or both.
Fields are defined per tenant and linked to locations. If multiple locations need the same field (e.g. all your French sites need SIREN), you create it once and assign it to each location.
Important: There is no input validation on field values. It's your responsibility to check that customers or staff enter correct information.
Step 1: Open location settings
Navigate to the location where you want to add custom invoice fields.
Go to Location Settings and find the Invoice Settings card.
Step 2: Add a new custom invoice field
Click Add Custom Invoice Field to open the configuration dialog.
Name - enter the field label. This must be unique across your tenant. Keep it short and clear, as it appears directly on the invoice.
Field level - choose Customer or Booking.
Customer: the value is stored on the customer record and reused across all their bookings and invoices. Use this for identifiers like SIREN or passport numbers.
Booking: the value is stored on a single booking. Use this for references that change per booking, like a purchase order number.
Customer type (shown when you select Customer level) - choose Business, Private or both. Only the relevant fields will appear when you create or edit a customer of that type.
Click Save to create the field.
Important: Each location has a limit on how many custom invoice fields you can configure. You can set up either:
1 field for private customers and 1 field for business customers, or
1 field that applies to both private and business customers
Field names are unique across your entire tenant. If another location already uses the same field, you can reuse it rather than creating a duplicate.
Step 3: Set field values on a customer
Once a custom invoice field is configured for a location, it appears on the customer record.
When creating a new customer
During customer creation in the Manager, after selecting the location, the relevant custom invoice fields appear in the form. Enter the value (e.g. the customer's SIREN number) and continue with creation as normal.
[Screenshot: Customer creation form showing a custom invoice field input]
On an existing customer
Open the customer's detail page in the Manager. You'll see a section for custom invoice fields. Click Edit to add or update the value.
The field is optional in the Manager, so you can leave it blank and fill it in later.
[Screenshot: Customer detail page showing the custom invoice field card with an Edit option]
Step 4: Verify fields on invoices
When a custom invoice field has a value set for a customer, it appears automatically on all related invoices. This includes:
Booking creation invoices
Standard invoices
Booking adjustment invoices
Deposit invoices
Late fee invoices
The field name and value are passed to Stripe and appear on the PDF invoice alongside existing information like the VAT ID and customer number.
Important: If a field has no value set, it won't appear on the invoice. Only fields with data are shown.
Examples
SIREN (France)
A French operator needs the SIREN number on invoices for business customers.
Name: SIREN
Field level: Customer
Customer type: Business only
When the operator creates a business customer, a SIREN field appears. The number is stored on the customer and printed on every invoice.
Purchase order number (Belgium)
A Belgian operator's customers need their internal PO number on every invoice so their procurement team can match invoices to orders.
Name: Purchase Order Number
Field level: Customer
Customer type: Business only
The operator enters the PO number on the customer record. It then appears on all invoices for that customer.
Passport number (Spain)
A Spanish operator needs to collect a passport number for private customers who don't have a national ID.
Name: Passport
Field level: Customer
Customer type: Private only
When the operator creates a private customer, a Passport field appears. The value is stored on the customer and included on all their invoices.
Notes to keep in mind
Field limit per location: you can set up either 1 field for private customers and 1 for business customers, or 1 field that covers both. This means a maximum of two custom invoice fields per location.
Roles and permissions: only operators with the Admin or Franchise Admin role can create, edit or delete custom invoice field settings. Other roles can view and fill in values on customers.
No input validation: Kinnovis does not validate the format of field values. If a SIREN must be 9 digits, you'll need to verify this yourself.
Editing fields: you can update whether a field is collected in the Booking Portal and whether it's required. Renaming a field is only possible if no values have been set against it yet.
Deleting fields: removing a field from a location unlinks it rather than deleting it permanently. This means existing invoice data is preserved.
Customer Portal: customers cannot currently view or edit custom invoice fields in the Customer Portal. You'll need to collect and enter this information on their behalf.
Coming soon
We're actively working on two additions to custom invoice fields:
Custom fields on bookings (Manager)
Operators will be able to set custom invoice field values directly on a booking in the Manager. This is useful for fields like purchase order numbers that vary per booking rather than per customer.
Custom fields in the Booking Portal
Customers will be able to fill in custom invoice fields during the booking process in the Booking Portal. You'll control whether the field is optional or mandatory. If a returning customer is missing the value, they'll be prompted to enter it when making a new booking.
These updates will be released shortly. We'll update this article once they're available.