For US companies, on the team page, there is a tax compliance column.
You will be able to see which contractor has completed their tax compliance form and whose form is still missing.
By clicking on the form, you can view and download the form.
There are two ways to add a tax compliance form to Oyster.
1) Contractors can complete the tax form on Oyster - help page
2) You can upload a completed tax form - help page