(MONEY Magazine) – MORTGAGES Q. The people at my national bank recently sent me a letter saying that they had forgotten to notify me about a rate increase on my mortgage a year ago and that I now owe $3,667.08 in back interest. Both the bank and I had previously signed a note saying they would notify me in a ''timely manner'' about such increases. What can I do?

Ken Nolan San Diego

A. The federal Truth in Lending Act requires banks to notify a customer at least 25 days before a rate hike. If the Comptroller of the Currency, the federal agency that regulates national banks, finds that your bank violated this rule, it could fine the bank or even order it to forfeit the increase. To file a complaint, ask the Comptroller of the Currency (Consumer Activities Department, 490 L'Enfant Plaza East S.W., Washington, D.C. 20219; 202-447-1600) for a complaint form. A decision could take two months to two years, depending on the complexity of your case. In the meantime, you do not have to pay the increase. If the ruling goes against you, however, you might have to pay interest on the overdue amount.

COLLEGE SAVINGS Q. I'm puzzled about whether to save for my daughter's college education with a Uniform Gifts to Minors Act (UGMA) account. I have read that colleges assess a child's assets more dearly than the parents', meaning a large UGMA account could hurt my daughter's chances of getting financial aid. Is this true? David Sewell Rochester, N.Y.

A. Yes. The government can require your daughter to contribute annually up to 35% of her assets -- including checking, savings and UGMA accounts -- to her % education in order to qualify for certain federal loans. But it can insist that you contribute only up to 12% of your assets after deductions for living expenses. The sole circumstance under which your daughter would be eligible for the 12% cap would be if she is financially independent of you (as defined by the financial aid rules) and has dependents of her own. For a comprehensive summary of the rules, ask the Office of Student Financial Assistance (U.S. Department of Education, 400 Maryland Ave. S.W., Washington, D.C. 20202; 800-333-4636) for the free booklet The Congressional Methodology: 1988-89.

TAXES Q. My husband and I have had to move away from our home for a year. We have rented it out on a one-year lease, since we intend to return next year. How should we handle this when filing our 1988 income tax return? Catherine R. Bartholomew Pittsburgh

A. The Internal Revenue Service will consider your home a rental property for the portion of 1988 that it was leased. Hence, you must report any rental income on Schedule E. To offset that income, you deduct all expenses of renting and maintaining the property, including agent's fees, repair work and a prorated share of property taxes, mortgage interest, homeowners insurance and depreciation. For the time that you lived in the house, you may deduct mortgage interest and real estate taxes on Schedule A as usual.

COLLECTIBLES Q. I have an old paper picture of Abraham Lincoln that I have been told is an early form of photography called an ambrotype. Is it valuable? Reba Cram Tishomingo, Okla.

A. Since yours is a paper print, it cannot be an ambrotype. Ambrotypes were portraits made on treated glass in the 1850s and early 1860s. An original Lincoln ambrotype could fetch $50,000 today. A vintage photograph, however, could still be worth several thousand dollars, depending on its size, pose, condition and rarity, according to Lloyd Ostendorf of the Lincoln Picture Studio in Dayton. For a free appraisal, send a photo and description of your print's condition to Sotheby's Photographs, 1334 York Ave., New York, N.Y. 10021.

INSURANCE Q. I own a cigar stand in Manhattan and pay $4,753 a year for major-medical insurance. My wife and I can't afford this anymore. Is there any other alternative? Stuart Landau Whitestone, N.Y.

A. Yes. Often you can reduce your premium by raising your deductible or increasing the percentage of medical bills that you pay. Or you can switch to less expensive coverage, such as Prudential's major-medical policy ($2,109 a year with a $300 deductible), Aetna's comprehensive medical policy ($2,722 a year, $500 deductible) or Traveler's major-medical policy ($2,947 a year, $500 deductible). You can find their phone numbers and addresses, as well as a diagnosis of their financial health, in the Life-Health edition of A.M. Best's Insurance Reports, available at most libraries.

PENSIONS Q. My company is switching from a defined-benefit retirement plan to a defined-contribution plan. What's the difference? J.L. Richardson Burbank

A. In a defined-benefit plan, which covers about half of the 40% of U.S. workers protected by these two types of plans, your company provides benefits according to a formula based on such factors as how much you earned while working and how long you were employed. Under a defined-contribution plan, your payments -- and your employer's -- are fixed by the plan's rules. The level of your retirement benefits depends on how well the plan's investments perform.

MUTUAL FUNDS Q. I have bought shares in several mutual funds periodically over the years but haven't kept any records. If I sell these shares, will the fund send me a statement showing capital gains or losses? If not, how do I know what to tell the IRS? William Krause Beverly Hills, Fla.

A. Sorry, it's up to you to calculate any gains or losses. But your fund's management company can provide the data you need. Funds normally keep shareholder records dating back five to seven years, and they can send you duplicates of your year-end statements, which show all transactions for each year. From these statements, you can determine the cost of the shares you have bought over the years. For a more detailed explanation, see Investing Basics on page 145. You can also consult IRS Publication 564, Mutual Fund Distributions, which you can get free by calling 800-424-3676.