onboarding asks for our SIC code or industry code which one do I enter

SIC code usually follows from the SBI code in the Business Register

There is no separate "SIC code" that you need to look up or request separately. Onboarding forms from banks and insurers usually ask for this because their system works internally with SIC codes, while your business is registered in the Netherlands with an SBI code. In practice, you enter the SBI code as it appears with the Chamber of Commerce, or the bank/insurer translates it themselves to their own classification. If you are unsure which format they want, look at the example or the tooltip in the form itself — some portals accept SBI directly, others ask for a NACE or SIC equivalent and look it up themselves based on your SBI code.

More important than the exact code language is that the answer is consistent with what is already recorded about your business. This topic belongs to the same question as in which sector is the enterprise active: both questions lead back to the same source, and a different code in one form versus another will stand out during a review. So use the same starting point each time, even if the portal uses a different label for the field.

Where the source data comes from

The SBI code that serves as the basis is one of the data that, according to the Business Register Act 2007, is recorded for every business with the Chamber of Commerce. This makes it the appropriate source: not the description that a bank or insurer comes up with themselves, but the code that belongs to the registration. If your SBI code no longer appears, or if the question is part of a broader identity block, it is often located together with the registration number under which the enterprise is registered in the same chain file, so you do not have to look it up again each time.