Taxe setup for sales orders

Hi Team,

I have a requirement to setup 10% tax for a pirticular item & pirticuar customer . For the remaining items the tax is always zero for that customer.

I have enabled Item validation in P4008 processing options.

I have added tax rate area with 10% for that item in p4008 and added the tax rate area to customer in customer master.

Now my query is, is it required to setup Zero tax also for the same tax rate area in P4008 or system will give Zero tax automatically as we have defined only for one item in setup.

Please advise.