US Social Security for US citizens residing abroad.
U.S. citizens who are residents of the following countries are exempt from U.S. tax on their benefits:
• Canada.
• Egypt.
• Germany.
• Ireland.
• Israel.
• Italy. (You must also be a citizen of Italy for the exemption to apply.)
• Romania.
• United Kingdom.
https://www.irs.gov/pub/irs-prior/p915--2024.pdf page 5.