So I've just ordered the newly announced Z Fold and Watch, and noticed after ordering that the sales tax on Samsung's invoice is higher than my local sales tax rate. My billing and shipping address are both in Seattle, WA, which has a state+county+city sales tax rate of 10.25%, but Samsung charged 11.275%.
Posting here (1) as a PSA for others to check their invoice, and (2) wondering if there's some obvious thing I missed.
The order is as follows (payment summary screenshot attached to this post):
Galaxy Z Fold 512GB: $749.99
original $1919.99, -$120 free storage upgrade, -$1000 for iPhone 14 Pro Max trade in, -$50 for reserve credit
Samsung Care+: $167.30
original $239, -$71.70 "limited time" discount
Galaxy Watch 6 Classic 43mm LTE: $225
original $449.99, -$224.99 bundle discount
So, subtotal is $1142.29 as expected. Sales tax in my location is 10.25% (verified here), so the sales tax should $117.08, but instead it's $128.79, $11.71 higher than it should be.
Oddly, it's off by exactly 10% (of the expected sales tax amount).
I contacted chat support and all they could do was file a ticket internally and tell me they'll follow up in 2 business days. Screenshots of chat support: https://imgur.com/a/bdAaot7
FWIW, I ran this through the GPT-4 Code Interpreter and it couldn't find an obvious answer. Trying out different combinations of taxable discounts also couldn't produce the same result. I do know Samsung has been criticized in the past for charging tax on various pre-discounted values though.