Do I need to register for self-employment tax in Israel if I work remotely for a foreign company?

If you are a tax resident of Israel — because your centre of life is in Israel, or you have been present for 183+ days in a tax year — then your income from working remotely for a foreign employer is Israeli-source income subject to Israeli income tax. You would need to register as a self-employed person with the ITA and file an annual return. If you are a genuine non-resident working entirely outside Israel for a foreign employer, Israeli tax generally does not apply. The distinction matters greatly and a tax advisor should assess your specific situation before you start work.