The interest you pay on a home mortgage is usually tax-deductible. You are allowed to deduct interest on multiple mortgages, as long as they add up to less than $1 million. The one criteria being that the money was used for buying, building or improving a home.

Every year, you should receive a "Form 1098" from your lender which details how much mortgage interest you paid. To claim this deduction, you need to fill out "Schedule A", under "itemized deductions" to record your interest deduction.

Home mortgage interest deductions can also include late payment charges and pre-payment penalties. The only requirement is that they were not for a specific service received in connection with your home loan.

Real estate taxes are also tax-deductible. Your interest statement should list the amount of real estate taxes you paid if your taxes and homeowners' insurance were placed in an escrow account when you closed on your mortgage. If your real estate taxes aren't included on the statement, review your cancelled checks to figure out the total amount of real estate taxes paid.

If you refinanced in the last year, you may be able to deduct any points you paid to buy down the mortgage rate. These points must be deducted proportionately over the life of the loan. For example, if you took out a 30-year mortgage, you would deduct 1/30th of the points each tax year.

Many homeowners have overlooked an important tax opportunity. If you have refinanced more than once, you can deduct unclaimed points from an earlier refinance. Let's take an example:

You refinanced in 2003 and paid points. You then deducted 1/30th of those points in 2003 and 2004. However, rates continued to drop, so you decided to refinance again in 2005, paying off the 2003 loan. The remaining points you have not yet deducted can now be deducted in 2005. You could also use this deduction if you sold the house in 2005, rather than refinancing.