From movies and television programmes people in the USA seem to be asked for their Social Security number on numerous occassions. I the UK I guess that the nearest equivelant is the National Insurance number, but I have only been asked for this for tax purposes and state benefits. Is the US version used for more general reasons?

According to Bill Bryson that is the case.

The problem is that a Social Security number (SSN) isn't supposed to be used for ANYTHING but Social Security. However, universities use it as your ID number (some do not), employers use it as your employee number, you're asked for it to open a bank account, open credit cards, etc. And that's where the problems start. All you need is a SSN and you can do all sorts of identity theft like open credit cards under someone else's name. Recently, some univeristy (I forget which) had 55,000 SSNs hacked! That's 55,000 people who now need to really check their credit reports and such VERY carefully, probably for the rest of their lives.

The US SSN should NOT be and never was intended to be an 'all-purpose' ID number - it was to be used to determine Social Security benefits only.

Also, a tip for people: Do NOT carry your SS card in your wallet. When I moved in with my current roommates and I saw that this is what they did, I cringed. Why don't carry it with you? Because on the off chance your wallet is stolen, the thief now has access to your photo ID, credit cards and SS number - each of which can be used in identity theft... but you can always get a new photo ID and cancel the credit cards - but that SSN is the hardest form to have a thief stop using. (I'm not sure, but I believe you cannot get your SSN reassigned if the card is stolen.)

At which stage of your life in the US are you allocated this number? In the UK a number is normally sent shortly before a person's sixteenth birthday or they can apply for one from the age of fiteen and a half upwards.

Sue, I believe you get one when you are born. The first group of numbers is the code for the state you were born in, or, if you are not born in America, it represents the state where you registered.

I got one when I became a legal resident alien in the US in 1980. In 1985, Maynooth (who is American) and I moved back to Australia (where I am from). When our daughter was born in 1990, I registered her birth with the American consulate here because she automatically has dual citizenship. They immediately issued her with a social security number.

I just talked to one of my friends who went to UT. He's clear. Apparently, his was not in the range of numbers they captured.

I am very set against having my SSN as an ID number. I try to fight it whenever I can. However, the above posters are right - the number is used for many things that you can't just say "I don't want to give you that info" to. You're forced to give it in some cases (that are not related to the purpose for which they were intended).