Is there a way to have taxes withheld with each transaction?
You have to download a second app like tax jar that integrates to do that. If you go to the app integration page you can find options there. You can also set aside an estimated amount using a RIZE checking account.
can you clarify what you mean with withheld? are you wanting taxes charged on a transaction, or are you asking about having the tax taken from your account and paid for you to the state?
you can set up taxes on items. https://squareup.com/help/us/en/article/5061-create-and-manage-your-tax-settings
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