NEW YORK — Charities are stepping up their donation requests in the wake of Hurricane Harvey, which has devastated South Texas and on Wednesday hit southwestern Louisiana. At least 18 people have died, and countless residents are displaced from their homes.

While the urge to donate clothes and other supplies is natural, money is the quickest, most effective contribution most people can make during times of disaster, charities and philanthropy experts say. And donating directly through a website gets money to a charity faster than a text donation, even though the text might seem easier.

Here’s how to make sure you are giving in a way that matters the most.


GIVE TO ESTABLISHED RELIEF AGENCIES

GuideStar’s website has a database that lets you vet charities . You can find information on a charity’s expenses, assets and revenue, as well as its programs.

Stacy Palmer, editor of The Chronicle of Philanthropy, also suggests looking at a charity’s website for information on how it will use donations. And look through local news reports for information on a charity’s work, or contact the local United Way and the local Community Foundation — in this case Houston’s.

It’s up to you whether to go with a local charity that might know the area better, or a national charity that has wider reach. Palmer says “both kinds of organizations have their place right now.”


TEXTING TO GIVE?

It might be tempting to make a donation through text and have the phone company charge it on your phone bill. It’s easy, and it might feel as though it’s the quickest way to get money to a charity.

But Palmer says that’s not the case, as charities have to wait for the phone companies to release the money.

The quickest way to give is to go to the charity’s website and donate directly, using a credit or debit card. That said, relief agencies will need money beyond first few days or even weeks, so if the ease of text donations appeals to you, tap away. To donate $10 to the Red Cross via text, send a text message saying “REDCROSS” to the number 90999.

Apple users in the U.S. can also donate to the American Red Cross through the company’s iTunes and app stores. Amounts range from $5 to $200, and you can’t use store credit.


TIMING

Donations often pour in immediately after disaster strikes but peter out during the long recovery process. While there are a lot of immediate needs, Palmer says, “charities are going to need support on the long haul.”

Consider saving some of your money so you can donate again in a few weeks or months. Better yet, set up a recurring donation to support your chosen charity over time.

Some charities will say when they have raised enough for a particular disaster and use any extra money for their general fund, Palmer says. This isn’t bad.

“One of the things this disaster shows is that it’s important to have resilience,” she says. “It’s smart to just give and say that it can be used wherever it’s most needed.”


CROWDFUNDING

Group fundraising services such as GoFundMe let people raise money for friends, families, neighbors or themselves — as well as for charity. As always, do your homework before giving to a stranger or cause online.

GoFundMe has a special page for Hurricane Harvey pleas for charities, individuals and families. GlobalGiving, a crowdfunding site for charities, is trying to raise $2 million for local relief and recovery efforts.

Remember that donations are tax-deductible only if they go to a registered non-profit or charity. Otherwise, they are generally considered gifts.


HOLD OFF ON MATERIAL DONATIONS

Donating food, clothing and household items can complicate and even hinder relief efforts, experts say. After Superstorm Sandy in 2012, for example, reports cited relief agencies not knowing what to do with the piles of clothing and other unsolicited items pouring in.

The U.S. Center for Disaster Information says such donations “require transportation — which is expensive and logistically complicated — and a pre-identified recipient on the ground who will receive the shipment, pay customs and other fees, sort and distribute the items.”

Unsolicited goods, the agency says , are “never required in early stages of response, and they compete with priority relief items for transportation and storage.”

It doesn’t mean there will never be a time or place for such donations — check with relief agencies as time passes. And a few charities have announced immediate needs for material donations; the Houston Humane Society has set up an Amazon wish list for the most needed items.


CONSIDER SPECIAL NEEDS

Seniors, the disabled, children and even pets are particularly vulnerable during disasters. Consider donating to charities that focus on their needs.

The Texas Diaper Bank , for example, says diapers (whether for babies or adults) are not provided by disaster relief agencies. Again, these charities need money — not boxes of diapers you picked up at Costco.

Save The Children is setting up “child-friendly spaces” inside shelters to give kids a safe area to play and get support from trained experts and “get a sense of normalcy” during disasters, spokeswoman Jordyn Linsk said. The organization is also distributing infant and toddler supplies.

Portlight Strategies helps people with disabilities, older adults and their families recover after disasters.

To help animals, check the San Antonio Humane Society, which has set up an emergency fund for pets and strays, or the Houston Society for the Prevention of Cruelty to Animals . And the Houston Humane Society needs money, too.


RELIGIOUS AND HUMANITARIAN GROUPS

Some of the religious organizations are “some of the strongest relief groups,” Palmer says.

Those accepting donations include Catholic Charities USA, International Orthodox Christian Charities , Islamic Relief USA , the Jewish Federations of North America and Tzu Chi USA , a humanitarian organization with Buddhist roots.


CHECK OUT MATCHES

Facebook says it will match every dollar raised through its service, up to $1 million, for the Center for Disaster Philanthropy’s Hurricane Harvey Recovery Fund. The money will support local recovery and rebuilding efforts. U.S. Facebook users are getting a message at the top of their news feed on how to donate.

Google, meanwhile, is matching $1 million in donations to the American Red Cross. To donate, go to http://www.google.org/harvey-relief . The company also matched donations from employees and said Tuesday it donated $750,000 between its nonprofit arm, Google.org, and employee contributions to organizations such as the American Red Cross, Habitat for Humanity and Save the Children.

Some companies, such as the Walt Disney Co., are also matching employee donations.