h1B visa holders have to pay taxes to the US on their income if they stay there for at least 183 days in a year. If they work abroad, they may also be taxed by the foreign country, but they can claim exclusions to avoid double taxation under tax treaties.

h1B visa holders working in the US are taxed as residents They have to report and pay their taxes to the USA government on their income abroad too. But they can claim foreign tax credits to avoid double taxation