On what line of which IRS tax form do I report income from my UK Old Age Pension?

I am a naturalized U.S. citizen (formerly a British citizen) living in the United States. Because I worked for many years in the UK, I am entitled to a UK Old Age Pension. I understand that this pension income is taxable, but I can't figure out how to report this income to the IRS since I did not receive a 1099-R from the British government.

Public Comments

1. If it's the equivalent of social security (a public pension scheme) not a private pension or a pension for government work, put the amount on the line for social security.
2. If your payment is the British equivalent of US Social Security, it does not appear on your US Tax Return and is not taxable. The US and GB do not tax each other's equivalent of Social Security, due to a tax treaty.