Sales Tax rates change periodically, even sometimes in the middle of a calendar year. If you have saved Sales Order, Receivable, or Purchase Order Invoice transactions, simply changing the tax rates will not update these saved transactions. Running the Regenerate Sales Taxes routine saves you from having to rekey lines to recalculate sales taxes.

The utility is found on the Administration page in GP under Utilities then Company then  Regenerate Sales Taxes.

Let’s look at the details that are part of Tax Schedule ID USASTCITY-6* and their calculated amounts on saved sales documents.

I updated the two tax details that are on that schedule.

We can run the Regenerate Sales Taxes Utility now. We will run it only for Sales Order documents for now.

Do not skip taking a backup first.

You will get a listing of those sales line items that were updated.

Let us look at the results and changes to Tax Schedule ID USASTCITY-6*

You can dig much deeper and use Effect Dates for Taxes.

To activate, mark Use Date-effective Tax in the Company Setup. Choose either Document Date or Posting Date upon which to calculate sales taxes.

To use Date-effective Tax dates, click the Date Effective Tax Rates in the Tax Detail window.

Finally, use Mass Modify Taxes to mass modify a range of tax details and effective dates.

Select what we want to Modify, either details, effective dates, or both.

Enter a range of Tax Details and click insert. If the range includes details that do not need to be updated, right-click the detail row and choose Delete Row.

Use the Regenerate Sales Tax Utility after Effective Dates and Mass Modify.