As you put the finishing touches on your tax returns, remember that while U.S. companies face tax rates of 35% (the highest in the advanced industrial world) many don’t actually pay that much. Instead, they choose to keep their profits offshore. The last few decades have seen a steady–and perfectly legal–accumulation of income in havens like Bermuda and the Cayman Islands. Apple, for instance, now has more than $200 billion offshore. The 50 companies that keep the most money offshore combined this year to keep a total of $135 billion from the IRS, new figures from Oxfam, the international charity, show. Historically, they’ve kept an astounding $1.36 trillion in total revenue out of the U.S., so it won’t be taxed.
The top five spenders on tax lobbying were General Electric, Verizon Communications, Comcast, AT&T, and Exxon Mobil, together accounting for a quarter of all tax lobbying by the top 50 companies. The companies with the most money offshore are Apple, Pfizer, Microsoft, GE, IBM, and Merck, according to the report. In 2015, the top 50 had a total of 1,751 subsidiaries in tax havens, while receiving a total of $423 billion in various federal tax breaks.
This untaxed money sits idle, doing little for Apple’s–or any other company’s–productivity. It’s lost to R&D departments, to investors, and to U.S. taxpayers. Most experts, left and right, agree that we should work to get that money home where it can be more useful. And, indeed, corporate tax “reform” now being considered by Congress aims to do just that. Republicans want a tax repatriation “holiday” of 10% (instead of 35%) to encourage companies to invest their money in this country, as well as a cut to the normal corporate rate to 20% (Trump actually called for 15% during the election). At the same time, they’ve also proposed something called “border adjustment,” which effectively taxes imports at a rate 20% higher than exports. That way, the argument goes, companies are encouraged to make stuff in the U.S. instead of importing it from China or another low-cost locale. Even Democrats may be open to modest corporate tax reform: President Obama proposed lowering the rate to 28% and one-time holiday at a 14% rate.
Oxfam, however, makes a strong case that these changes, while decent in theory, won’t have the positive economic effects that their proponents claim. While repatriation might save the 50 corporations more than $300 billion in taxes, there’s no guarantee they’ll spend it on things that benefit ordinary people. In 2004, during the Bush administration, another repatriation period resulted in a net loss of 20,000 jobs, $3.3 billion in lost revenues for the U.S. Treasury, and ongoing incentives for companies to stash even more money offshore, a U.S. Senate investigation found. Pfizer, for instance, brought home $35.5 billion in overseas earnings, but cut 11,748 jobs in the U.S. between 2004 and 2007.

Meanwhile, the Border Adjustment Tax (BAT) could lead to higher prices for clothing, gasoline, and electronics, hitting low-income Americans the most. And it could be disastrous for poorer countries, Oxfam argues. The BAT would remove taxes on exports and stop companies from deducting imports as business expenses. That would make it harder for foreign companies to sell goods into the U.S., and probably raise the cost of paying debts dominated in dollars. Many economists think a BAT would cause the dollar to appreciate, meaning that anyone holding dollar-debt would effectively have to pay more than before. Turkey, for instance, has dollar debts equivalent to 50% of Turkish gross domestic product, Oxfam says. Moreover, a BAT wouldn’t necessarily stop tax evasion. Rather it would create a different “game of whack-a-mole,” the charity says.

Correction: This article previously misstated the tax amount avoided by companies this year: It’s $135 billion for 2016, and they’ve also kept $1.36 trillion–not billion–off shore to date.