As President Trump’s tariffs have ratcheted up in recent months, so have the mysterious solicitations some U.S. companies have received, offering them ways to avoid the taxes.

Shipping companies, many of them based in China, have reached out to U.S. firms that import apparel, auto parts and jewelry, offering solutions that they say can make the tariffs go away.

“We can avoid high duties from China, which we have already done many in the past,” read one email to a U.S. importer.

“Beat U.S. Tariffs,” a second read, promising to cap the tariffs “at a flat 10%.” It added: “You ship worry free.”

“Good News! The tariffs has been dropped finally!” another proclaimed.

The proposals — which are circulating in emails, as well as in videos on TikTok and other platforms — reflect a new flood of fraudulent activity, according to company executives and government officials. As U.S. tariffs on foreign products have increased dramatically in recent months, so have the incentives for companies to find ways around them.

The Chinese firms advertising these services describe their methods as valid solutions. For a fee, they find ways to bring products to the United States with much lower tariffs. But experts say these practices are methods of customs fraud. The companies may be dodging tariffs by altering the information about the shipments that is given to the U.S. government to qualify for a lower tariff rate. Or they may physically move the goods to another country that is subject to a lower tariff before shipping them to the United States, a technique known as transshipment.