Tax for Online Orders

[hotstrawberry]

Can anyone explain why a higher rate is charged at the time of order, only to be re-calculated once payment processes?  State rates are known and we enter our address, so why make it confusing?  I'm just trying to understand because my bank balance is always off because of this.

[DaneeBT]

@hotstrawberry At checkout, it says “Estimated Tax,” and the highest possible tax amount will be shown and used for the initial authorization amount. However, once the order is shipped, the correct tax amount will be charged, which might be less than the amount you were originally shown. I'm sorry this has caused confusion and I'll share your feedback with the appropriate team. 

[hotstrawberry]

I understand WHAT is happening, I would like to know WHY?