Here are a few things you can do to correct the sales tax calculation in Shopify:
Check your tax rates. Make sure that the tax rate for Michigan is set to 6%. You can do this by going to Settings > Taxes and Duties > Taxes.
Check your rounding settings. Shopify uses a default rounding method of Up to Nearest Even Cent. This means that any amount below 0.5 cents will be rounded down, and any amount above 0.5 cents will be rounded up. You can change this rounding method by going to Settings > Taxes and Duties > Rounding.
Use a tax calculator. There are a number of online tax calculators that you can use to verify the sales tax calculation. This can be helpful if you’re not sure whether the tax rate or rounding method is correct.
If you’ve checked all of these settings and the sales tax calculation is still incorrect, you can contact Shopify support for help.
Here are some additional tips for ensuring that your sales tax calculations are accurate:
Keep your tax rates up to date. Tax rates can change frequently, so it’s important to check your rates regularly to make sure that they’re accurate.
Use a tax calculator. As mentioned above, there are a number of online tax calculators that you can use to verify your sales tax calculations.
Be aware of local tax laws. Sales tax laws can vary from state to state and even city to city. Be sure to understand the local tax laws in the areas where you sell products to avoid any penalties.
I hope this helps!