A vendor onboarding form has a problem a client form does not: the vendor is doing you a favour by filling it in, and they are not yet being paid. Long forms come back late or half completed, and chasing them costs more than the fields were worth. This page is about which fields earn their place, and about pricing the rest in the vendor's own minutes instead of arguing about them.
Why vendor forms come back late
Because the incentive is the wrong way round. A new client filling your intake form is invested; a vendor filling your onboarding form is doing unpaid administration before a purchase order exists. Every additional field lowers the probability the form comes back this week, and the firms with the shortest forms are the ones whose vendors are set up fastest.
The fields that earn their place
Legal entity and taxpayer identification, which for a US vendor centres on Form W-9. Remittance details. A contact for invoices and a contact for the work, which are frequently different people. Whatever evidence your firm requires, with its expiry date. Anything beyond that should be asked for when it is needed rather than at the front door.
Pricing the rest
Count the fields, count the required ones, put in your own seconds per field, and the optional half has a price in the vendor's minutes. The free intake worksheet on this site does that arithmetic and adds the minutes each requested document costs them to find. It is the same tool as for clients, because it is the same problem.
Where the answers should land
Structured, against the vendor record, so nobody retypes them into the payment system. Retyped bank details are a category of error with real consequences, and every retyping step is another place for one to enter.
Questions people ask about vendor onboarding form
Should the form be sent before or after the agreement?
Alongside it. Waiting until the agreement is signed adds the form's turnaround to the start date for no benefit.
Can vendors fill it without an account?
They should be able to. Asking a vendor to register somewhere before they can give you their bank details is a reliable way to slow the whole thing down.
What is the most commonly missing field?
A separate invoicing contact. The person who sells to you is usually not the person who chases payment.