Not having a loved one’s SS number is more common than you might think. However, it’s crucial to have this number to complete the death certificate and to apply for benefits. If you don’t have this number, here are some places to look: Speak with your loved one’s place of employment. They are required to have the SS number of all employees and freelancers, so they should be able to help you with this information. If your loved one wasn’t employed, try to find their last employer. They will still have records of previous employees on file, including Social Security numbers.