To add a new tax period, please follow the steps below.
First, select a client for whom you would like to add a new tax period. Then, select the Plans tab and select the client's plan.
Next, select Taxes and click Add New Taxes.
To name the tax period, select Edit and enter the name of the tax period.
From here edit the Tax Rate (%), Start Year / Age, and End Year / Age. As a convenience for you, you only need to enter either the year or the age of the client. The other will be automatically calculated for you. Also, remember to use the effective tax rate, not the marginal rate. Click the Save Tax button once your done.