Most of us feel happy when we unexpectedly find a $20 bill in the back pocket of our old denim or under the couch. Well, what if you found out that a decent chunk of money that's rightfully yours floating around somewhere waiting to be accessed?

Around 10 percent of the country's population has unclaimed money or property. But you need to look in the right places to find these unclaimed funds.

What are unclaimed funds?
These assets are rendered unclaimed when a business, government office, or financial institution cannot locate or contact an individual who owed funds or property. These funds are generally handed over to the government after a certain amount of time, and they stay with the government until the rightful owner makes a claim.

A common scenario in which people have unclaimed funds is when they open accounts with financial institutions but don't use them for a year or so, prompting the institution to contact the account owner. If the institution fails to contact the owner, they may declare the money unclaimed and turn it over to a state or federal agency. Similarly, there are other reasons for unclaimed funds, such as forgotten bond savings, accounts from bank and credit union failures, insurance accounts or annuities, unpaid wages, pensions from past employers, insurance and tax refunds, and 401(k).

How do you find unclaimed funds?
You can contact these government agencies to find unclaimed funds and assets:

National Registry of Unclaimed Retirement Benefits
When people change jobs, they often forget about a small balance in their previous employer's retirement plan. If you want to know whether you have any unclaimed money from an old job, visit the National Registry of Unclaimed Retirement Benefits' official website. This public service organization helps former employees locate lost or forgotten benefits.

Federal Deposit Insurance Corporation
Some people have unclaimed funds in old bank accounts. These funds can be in the form of insurance premium refunds, utility account deposits, dividend payments, and escrow accounts, among others. You can even receive unclaimed money from banks and credit unions that failed from Federal Deposit Insurance Corporation's and National Credit Union Administration's websites, respectively.

State Departments of Taxation
Occasionally, the Department of Taxation cannot find a taxpayer when an incorrect address is submitted or if moved without updating the address with the tax authority. In such cases, tax refunds become unclaimed funds. The National Association of Unclaimed Property Administrators allows you to quickly search for unclaimed tax refunds in states where you have or had an address.

Internal Revenue Service (IRS)
Billions in income tax refund checks are left undelivered or unclaimed each year. The reasons are incorrect addresses, incorrect bank account information, and taxpayers changing locations. You can contact the IRS to inquire about lost tax refunds or unclaimed money.

Department of the Treasury
Do you think you have lost, stolen, or destroyed savings bonds but cannot locate them? Get in touch with the Treasury's Bureau of the Fiscal Service. You'll likely be required to submit Form 1048 to claim your money and assets. Even the unclaimed funds from the IRS go to the Department of the Treasury if they aren't claimed within three years.

Social Security Administration
If a relative has recently passed, you might be eligible to receive life insurance benefits, so make sure you collect that. Also, if you bought a policy from a company that demutualized, it may owe you cash or stock. The Social Security Administration can help you search for an unclaimed life insurance policy.