In this modern age, it can be easy to believe you amount to little more than a number to your bank, insurance company, or your dry cleaner.

If you worry that your mother's the only one who still remembers your name, you might be right. More and more, you are your Social Security number. Use of the Social Security number has grown far beyond its original purpose of making sure the government keeps an accurate record of your earnings to determine and monitor your Social Security benefits.

Many businesses now routinely ask for a Social Security number during transactions large and small. (Would you like fries with that? Can I have your Social Security number?)

The problem is that the more that number gets out, the more vulnerable you may be to identity theft. With a Social Security number, a thief can do a lot using your good name, from getting a job to spending a ton of money on fraudulent credit cards.

Start with the understanding that not everyone's entitled to get your number, and you'll be on safer ground. When you hand out your Social Security number, you usually do so voluntarily.

You'll have to give your Social Security number to your employer. That's why it was created, after all. Some government agencies can also require that you divulge your Social Security number. Many more will request it. Often you'll encounter the question when doing anything related to taxes, or when you're applying for a government loan or benefits. That might include a student loan or a driver's license.

When a federal, state, or local government agency asks for your Social Security number, it is required to tell you whether a law requires that you disclose it or whether your cooperation is voluntary. They're also required to tell you what they'll do with the information and what the consequences would be if you don't want to cooperate.

Private businesses aren't required to be so forthcoming, but there's no reason you can't hold them to the same standard. Before you agree to give out your Social Security number to any private company, ask the business why they need the number, how it will be used, and what privacy protections will be in place. Ask, also, whether there's a law requiring you to disclose the number and what will happen if you refuse.

Banks, for example, must report a lot of transactions to the IRS, and they'll need your Social Security number to do that. You'll probably find it almost impossible to do banking, investing, and many other money transactions without sharing your Social Security number. The same thing will be true for virtually any situation in which you're applying for credit.

That doesn't mean that your bank or brokerage has to use your Social Security number as your online login or password. If your financial institution does, press them for an alternative. Online use of your Social Security number may expose it to computer hacking.

Many businesses have no good reason for requesting the number, other than the fact that it makes their record keeping easier. Unfortunately for the consumer, there's no law requiring businesses to come up with another identifying number if you refuse to divulge your Social Security number. They can refuse to do business with you, which can be inconvenient.

In those cases, you might have to press your point. Work your way up the company ladder to see whether you can find someone willing to give you an alternative identifying number to replace your Social Security number. Be ready to request alternatives.

If you have any doubts about whether your number will be protected, ask the business for its policy on Social Security number protection in writing. You can also protect your number by leaving your Social Security card at home, in a safe place, at all times. Don't print the number on your personal checks, and don't use it for any of your computer logins or passwords.

Then call your mother and tell her how much you appreciate that you'll never be just a number to her.

Motley Fool Green Light has money answers large and small. Consider a free trial to learn more today.

Related Foolishness:

Fool contributor Mary Dalrymple welcomes your feedback.