I'm starting full-time remote employment with a US company soon, and they asked me to fill up the W-8BEN form. So what should I fill up on the part of Claim of Tax Treaty Benefits? I found that NZ has a Tax Treaty with US, https://www.irs.gov/pub/irs-trty/newzld.pdf, but I still have no clue what I'm looking at
I believe you don't need to fill out the part on Claim of Tax Treaty Benefits. If you are not a US citizen or resident alien for US tax purposes, and you are not working in the US, your income should not be subject to US tax, and thus there would be no need to claim any tax treaty benefits for US tax purposes.