Your social security number is one of the most valuable numbers to your financial security and identity thieves know this, so knowing when not to give it helps reduce the chances of thieves getting it.

The following instances do require your social security number:
Credit Applications
When applying for certain federal benefits
Cash transactions over $10,000
Military paperwork
The Department of Motor Vehicles (driver’s licenses)

However, if you are filling out a form at a doctor’s office, for instance, you can leave it blank and hope they don’t pursue it. If you are still asked for it, it is reasonable for you to inquire why they need it. They only legitimate reason should be that if you were to die in the doctors’ care he would be required to put it on your death certificate. In this case, if you have provided contact information for someone who can provide that information then you should not have to provide it. If they still insist you can either request to give it to the doctor directly or as a last resort, you can make up a number. To avoid using someone else’ number you should put double zeros in the place for two numbers, no social security number has that.