If you feel that reaching your senior years means that you receive more letters and phone calls appealing for money, you discovered why professional fund-raisers often call age 65 and above "the golden years."

Many nonprofit organizations reach out to seniors because they generally have more disposable income and a greater tendency toward charitable giving. That means that older Americans are more likely to contribute to worthy causes.

But it also means that seniors often face a sensitive question: Who is worth my contribution? It's not just a matter of sifting out which charity receives a gift, but whether a group uses the money mostly for the organization's work or mostly for administration.

There is also a perennial question that faces donators of any age: How do I know if the group is legitimate? You can make these decisions wisely if you plan your giving and remember some basic guidelines.

Treat charity giving like any other part of your financial planning. Determine the amount of an annual or monthly gift in relation to your income and expenses.

If you are just plain annoyed about receiving a spate of mailed appeals for contributions, decide which charities you want to support and discard appeals from other groups.

Also, write the unwelcome sender and asked to be removed from its mailing list. Another tactic is to send a written request for removal to the Mail Preference Service, Direct Marketing Association, P.O. Box 9008, Farmingdale, NY 11735-9008. Both approaches could take up to three months before you are removed.

But what if the cause looks worthy? How can you know if the organization is an honest charity, not a scam?

Check the Better Business Bureau at www.bbb.org. The bureau's Philanthropic Advisory Service provides impartial and expert advice that will help you know whether a charity is following ethical fund-raising practices.

According to the bureau's Web site, some of the tips include the following:

*When you are approached for a contribution for your time or money, ask questions and don't give a donation until you're satisfied with the answers. Charities with nothing to hide will encourage your interest. Be wary of a reluctance or inability to answer questions.

*Ask if your contribution is tax-deductible. Contributions to tax-exempt organizations are not always tax deductible.

*Ask if the charity is licensed by state and local authorities. Registration or licensing is required by most states and many communities. However, remember that registration does not imply that the state or local government endorses the charity.

*Beware of statements such as "all proceeds will go to the charity." This can mean that the money left after expenses, such as the cost of written materials and fund-raising efforts, will go to the charity. These expenses can make a big difference, so check carefully.

*When asked to buy candy, magazines, cards, or tickets to a dinner or show to benefit a charity, be sure to ask what the charity's share will be. You cannot deduct the full amount paid for any such items, as the IRS considers only the part above the fair-market value of the item to be a charitable contribution. For example, if you pay $10 for a box of candy that normally sells for $8, only $2 can be claimed as a charitable donation.

*Don't give to a charity that uses pressure tactics such as intimidation, threats or harassing calls.

*Don't give cash; always make contributions by check and make your check payable to the charity, not to the individual collecting the donation.

*Keep records of your donations (receipts, canceled checks and bank statements) so you can document your charitable giving at tax time. Although the value of your time as a volunteer is not deductible, out-of-pocket expenses (including transportation costs) directly related to your volunteer service to a charity are deductible.

*Don't be fooled by names that look impressive or that closely resemble the name of a well-known organization.

*Check out the organization with your state's charity registration office (usually a division of the state attorney general's office) or with the local Better Business Bureau.

Mail appeals should clearly identify the charity and describe its programs in clear and specific language. Beware of appeals that rely heavily on emotion but tell you nothing of the charity or what it's doing about the problem it describes so well.

It is illegal to mail a bill, invoice or statement of "account due" that is an appeal for funds, unless it bears a clear and noticeable disclaimer stating that it is an appeal. You are under no obligation to pay unless you accept the offer. (Deceptive invoices are most often aimed at business firms rather than individuals.)

The same is true if the appeal is an invoice for unordered merchandise. If unordered items such as key rings, stamps, greeting cards or pens are enclosed with an appeal letter, remember you are under no obligation to pay for or return the merchandise. If payment is requested, inform the Better Business Bureau.

Finally, beware of appeals that include sweepstakes promotions, which should disclose that you do not have to contribute to be eligible for the prizes offered. To require a contribution would make the sweepstakes a lottery through the mail, which is illegal.