In the field in the form, you can set up a sales tax code to be calculated on the basis of one of these options:

– A tax rate is applied to the entire taxable amount. The taxable amount falls within a range (amount interval) that has a specific tax rate.

– The taxable amount is divided into parts, each of which falls within an amount interval that has a specific sales tax rate. The part of the amount that falls within a given interval is taxed according to the tax rate for that interval. The sales tax is the sum of the tax amounts that are calculated for each amount interval.
For taxes to be calculated on all taxable amounts—regardless of which method is selected—intervals must conform to the following rules:

The first interval has a lower limit of 0.

The last interval has an upper limit of 0, which stands for infinity.

The upper limit of any interval is the lower limit of the next interval.
If an amount is the upper limit of one interval and the lower limit of the next interval, the rate of the first interval applies to the amount.
If an amount falls outside the intervals that are defined by upper and lower limits, a tax rate of 0 is applied.
Note 

To set up tax intervals for the sales tax code that you select in the form, click . For more information, see Values of sales tax codes (form). 
Whole amount method of calculation: Example
The sales tax rates are set up in the following intervals:
Interval 
Tax rate 

0.00 – 50.00 
30% 
50.00 – 100.00 
20% 
100.00 – 0 
10% 
Method of calculation = Whole amount
Taxable amount (Price) 
Calculation 
Sales tax 

35.00 
35.00 x 0.30 
10.50 
50.00 
50.00 x 0.30 
15.00 
85.00 
85.00 x 0.20 
17.00 
305.00 
305.00 x 0.10 
30.50 
Each whole amount is taxed at the rate that is set up for its amount interval.
Interval method of calculation: Example
The sales tax rates are set up in the following intervals:
Interval 
Tax rate 

0.00 – 50.00 
30% 
50.00 – 100.00 
20% 
100.00 – 0 
10% 
Method of calculation = Interval
Taxable amount (Price) 
Calculation 
Sales tax 

35.00 
35.00 x 0.30 
10.50 
50.00 
50.00 x 0.30 
15.00 
85.00 
(50.00 x 0.30 = 15.00) + (35.00 x 0.20 = 7.00) 
22.00 
305.00 
(50.00 x 0.30 = 15.00) + (50.00 x 0.20 = 10.00) + (205 x 0.10 =20.50) 
45.50 