You could probably receive more help by calling the Internal Revenue Service and talking to an IRS representative
I do not see any other answers so I will attempt to tell you what I can on the subject.
India does not have Social Security System, so if you are in the U.S. for less than 5 years than you do not have to pay Social Security Tax and it does not have to be withheld from your check. The employer also does not have to pay Social Security Tax. This also applies to medicare taxes.
I cannot answer how Florida handles state taxes, you would have to contact someone in Florida associated with the Department of Labor.
The Federal Withholding taxes , SUTA and FUTA taxes would be on the number of days a year you spend in the U.S. and in what capacity. The L1-B visa is for someone that knows special knowledge of the companies operations.
The rules state for the India tax treaty with the U.S. That Wages, slary, and similar compensation that a resident of India receives for performing labor or personal services as an employee in the U.S. is exempt from U.S. income tax if these 3 conditions are met:
a) The employee is in the U.S. for no more than 183 days during the tax year
b) The compensation is paid by or on behalf of an employer that is not a resident of India
c) The compensation is not borne by a permanent establishemtn, fixed base, or trade or business that the employer has in the other country.
If you are a teacher or researcher at a University or a student or apprentice training at the company there are some different rules.
If you are a permanent resident of India (have resided in India for at least 365 days out of the preceding 4 tax years) (Also if you have resided in India for 9 years or more out of the preceding 10 years)
India taxes on worldwide income. This means that you could pay federal taxes to both India and the U.S. if you do not fall under that tax treaty standards mentioned above.
Some companies will equal out pay for expatriates and alien employees working for them to make the taxes more equal.
The only way you can be paid in India for work in the U.S. is if your company has a branch company office in India. At that point you could be paid by the office in India as an expatriate employee to the U.S. There are many different rules for Expatriates. The office in India would need to find out what the expatriate rules are to pay in this manner. They are too complicated and varied for me to write them in here and I only have the ones for a U.S. employee going to a foreign country.
A per diem is paid for travel. It is to compensate you for meals and lodging. It should be paid to you by the Florida office as you will be spending it in Florida.
Please contanct the Internal Revenue Service for more information on taxes and withholdings or more questions on per diems.
You can find the Internal Revenue Service at the following website;
Internal Revenue Service
Perhaps someone else on here has more detailed information, this is the best I can do to help.
Shirley