It's a nightmare for some former students: the Department of Education and guarantee agencies demanding payment from people who repaid their loans years ago. The Department or agency claims that the loan was never paid -- often the financial institution that originally loaned or collected the money is out of business -- and requires former students to prove they paid. This is obviously very difficult, as few people keep bank records.

If you face this problem and the financial institution from which you borrowed or repaid the money is still in business, solicit its help in getting copies of your canceled checks. If you're told that it doesn't keep such old records, ask workers there to check the microfiche and other electronic records.

If the financial institution is out of business or doesn't have your records, contact the federal agency that oversees the type of institution which had your records:

• National Banks. Office of the Comptroller of the Currency, 1301 McKinney Street, Suite 3710, Houston, TX 77010, 800-613-6743
  http://www.occ.treas.gov

• Federal Savings and Loans. Office of Thrift Supervision, 1700 G Street, NW, 5th Floor, Washington, DC 20552, 800-842-6929
  http://www.ots.treas.gov

• Credit Unions. National Credit Union Administration, 1775 Duke Street, Alexandria, VA 22314, 703-518-6330
  http://www.ncua.gov

• State Banks Members of the Federal Reserve System. Board of Governors, Federal Reserve System, 20th & Constitution Avenues, NW, Washington, DC 20551, 202-452-3946
  http://www.bog.frb.fed.us

• State Banks Not Members of the Federal Reserve System. Federal Deposit Insurance Corporation, 550 17th Street, NW, Room 100, Washington, DC 20429, 800-934-3342
  http://www.fdic.gov

Here are some examples of evidence you can use to prove you've paid up.

• If your former spouse or roommate remembers you diligently writing checks every month, have that person sign a sworn statement and send it to the agency.

• Dig up records from lenders for years past for copies of old credit reports listing payments made on the loan.

• Get copies of old tax returns -- from the IRS if necessary -- showing that you itemized the interest deduction on student loan payments back when that was permitted.

• Contact the school you attended for a report from the Department of Education showing the loan's status.

• Request a copy of the signed promissory note from the last holder of the loan with a summary of the account.

Finally, try contacting the Department of Education's Ombudsman at 877-557-2575. This office is available to assist people with student loan problems.