wrote
Is there any sales tax on the Vinyl replacement windows? Some
companies told me that there is one. But others say no and the price
for the windows should be everything. For example, if the price for 10
windows is $4k, it's 4k not 4k + sales tax. Which one is right?

Thanks!

On top of the other replies, here is another example of why some charge
sales tax, and some do not.

When buying wholesale, I can purchase tax exempt. I give them my tax ID #,
and charge the sales tax to the end user. If I'm going to purchase for my
own business, I do not claim exemption because I am the end user.

Some contractors use their SS# for ID, and go ahead and pay the sales tax.
This is usually done by smaller outfits. They usually roll the sales tax
into the job and do not collect separately.

In my State, you must have a Vendors # in order to collect sales tax.