I am a British Citizen going to be studying in the US

The exact language in US Immigration and Customs Enforcement’s guidance states: ‘A student on OPT may start a business and be self-employed. The student must be able to prove that he or she has the proper business licenses and is actively engaged in a business related to the student’s degree programme.'”

USCIS notes that those on an F-1 visa may not work off-campus during the first academic year, but may accept on-campus employment subject to certain conditions and restrictions. After the first academic year, USCIC notes that F-1 students can engage in three types of off-campus employment:

• Curricular Practical Training (CPT)
• Optional Practical Training (OPT) (pre-completion or post-completion)
• STEM Optional Practical Training Extension (OPT)

F-1 students could be eligible to work off-campus on a case-by-case basis as a result of special situations such as severe economic hardship or special student relief.

Most F-1 students are considered nonresident aliens by the IRS. As a nonresident alien, you will need to file form 1040-NR (federal tax return) to assess your federal income and taxes. Important: As of 2022, the IRS no longer uses form 1040-NR-EZ.

Not in the first year

Right

You will pay NON RESIDENT Tax in US and get a credit on UK tax

The same...you will pay tax in US because you are physically in the US and working but UK will allow a credit

You usually need to fill in a Self Assessment tax return if you’re a UK resident with foreign income. 

You are IN The US working so they will tax you.

Not by US Law

Generally, U.S.-sourced income includes all income received from U.S. organizations or individuals and compensation received from both U.S. and foreign organizations or individuals for work performed in the U.S.

Correct

You are welcome