Online shopping has been on the rise for at least two decades, but by all accounts 2019 has been a banner year for e-commerce.

Black Friday online sales hit $7.4 billion and Cyber Monday sales reached a record $9.4 billion, according to Adobe Analytics. And in April, Commerce Department figures showed for the first time in U.S. history that online sales edged past general-merchandise stores, including supercenters, warehouse clubs and department stores.

With so many of us making purchases online, especially around the holidays, it’s important to keep a watchful eye on our finances and information.

Research the product + seller

The Federal Trade Commission advises buyers to always do their homework beforehand. Check out multiple websites to compare prices and product descriptions and be sure to read customer reviews. Words like “refurbished,” “vintage,” and “close-out” may indicate that a product is in less-than-mint condition and name brand items offered at bargain prices could be counterfeits.

“Confirm the online seller’s physical address and phone number in case you have questions or problems,” the FTC says. “And if you get an email or pop-up message that asks for your financial information while you’re browsing, don’t reply or follow the link. Legitimate companies don’t ask for information that way.”

Pay by credit card + protect your information

Credit cards are the most secure form of online payment. Many cards offer additional warranty, return and purchase protections, but the biggest benefit is that credit card transactions are covered by the Fair Credit Billing Act. Under this law, cardholders can dispute certain charges and temporarily withhold payment until a creditor has investigated. If a credit card is used to make an unauthorized purchase, liability is generally limited to just $50.

Reputable sellers should ask for card and finance information directly through their websites or through other trusted platforms like PayPal. And beware of any email requests for information.

“Email is not a secure method of transmitting financial information like your credit card, checking account, or Social Security number,” the FTC says. “If you begin a transaction and need to give your financial information through an organization’s website, look for indicators that the site is secure, like a URL that begins with ‘https.’”

Know the signs of card + identity theft

The first clue to spotting a stolen card almost always takes the form of unusual and unauthorized purchases, so cardholders are encouraged to regularly monitor their expenses and accounts. But online shopping also opens consumers up to greater risk for identity theft.

Indicators of identity theft include unexplained withdrawals from bank accounts, disappearing bills or mail, data breach notifications and rejection of health care costs and coverage.

“Once identity thieves have personal information, they can drain your bank account, run up charges on your credit cards, open new utility accounts, or get medical treatment on your health insurance,” the FTC says. “An identity thief can file a tax refund in your name and get your refund. In some extreme cases, a thief might even give your name to the police during an arrest.”

Report stolen cards + online shopping fraud

Compromised cards should be reported to the issuer as quickly as possible in order to minimize financial liability. Most companies offer toll-free numbers and 24-hour services for such instances.

Online shoppers who run into payment and order problems can usually solve the issues at hand by working directly with the seller, buyer, or site operator. If that doesn’t work, consumers can also file complaints with with the Federal Trade Commission, their state Attorney General’s office, the Better Business Bureau and other county and state consumer-protection agencies.