President Trump has promised to generate a “massive” amount of revenue with tariffs on foreign products, an amount so big that the president said he would create a new agency — the External Revenue Service — to handle collecting the money.

“Instead of taxing our citizens to enrich other countries, we will tariff and tax foreign countries to enrich our citizens,” Mr. Trump said on Monday in his inaugural address, where he reiterated a promise to create the agency. “It will be massive amounts of money pouring into our Treasury coming from foreign sources.”

Much about the new agency remains unclear, including how it would differ from the government’s current operations. Trade experts said that, despite the name “external,” the bulk of tariff revenue would continue to be collected from U.S. businesses that import products.

Here’s what you need to know about what Mr. Trump has proposed.

The U.S. has an established system for collecting tariffs.

Tariff revenue is currently collected by U.S. Customs and Border Protection, which monitors the goods and the people that come into the United States through hundreds of airports and land crossings.

This has been the case nearly since the country’s inception. Congress established the Customs Service in 1789 as part of the Treasury Department, and for roughly a century tariffs were the primary source of government revenue, counted in stately customs houses that still stand in most major cities throughout the United States, said John Foote, a customs lawyer at Kelley, Drye and Warren.

With the creation of the income tax in 1913, tariffs became a minor source of government revenue, and after the Sept. 11 attacks, the customs bureau was moved from the Treasury Department to the Department of Homeland Security.

Customs officials today collect tariff revenue, but also monitor food safety, enforce intellectual property rights, inspect crops for pests and screen imports for goods made with forced labor, Mr. Foote said.

Creating a new agency is the provenance of Congress, not of the president, so it is not clear how the administration might go about establishing the new unit.

In an executive order issued on Monday evening, the president directed the leaders of Treasury, Commerce and Homeland Security to “investigate the feasibility of establishing and recommend the best methods for designing, building, and implementing an External Revenue Service (ERS) to collect tariffs, duties, and other foreign trade-related revenues.”

Tariff revenue rose in Trump’s first term and could grow

The money that the United States collected from tariffs grew significantly as Mr. Trump imposed levies on foreign metals, solar panels and thousands of goods from China in 2018 and 2019. The government collected $111.8 billion in trade duties, taxes and fees in 2022, up from $41.6 billion in 2018, according to Customs data.

That number could increase by multiples if Mr. Trump follows through on his promises to tax all American imports, and impose even higher levies on products from China. On Monday evening, Mr. Trump said that he planned to move forward with a 25 percent tariff on Canada and Mexico on Feb. 1, and was considering a universal tariff on all foreign products.

Mr. Trump and other Republicans are eagerly looking to tariff revenue to help to finance tax cuts. Still, tariffs are likely to earn just a tiny slice of what the United States takes in through income taxes. Economists say revenue from even very substantial tariffs would likely max out in the hundreds of billions of dollars, while the United States took in $4.2 trillion in income and payroll taxes last fiscal year. Tariffs would also decrease U.S. deficits, lower growth and raise consumer prices, the Congressional Budget Office calculated last month.

Tariffs are paid by importers

Mr. Trump insists that foreign countries pay the tariffs but it’s actually so-called importers of record — the companies responsible for bringing products into the United States — who pay tariffs to the government. Most importers sign up for a government electronic payment system, and the tariff fees are automatically deducted from their bank accounts as they bring products into the country.

Importers of record can be of any nationality: U.S. companies, U.S.-based divisions or branches of foreign companies, or foreign companies directly importing, without a business presence within the United States, Mr. Foote said.

But Richard Mojica, a customs lawyer at Miller & Chevalier, said U.S. importers “are usually U.S. companies.” He said that Mr. Trump had created confusion by saying that the External Revenue Service “would collect duties and tariffs ‘that come from foreign sources’ — a term that nobody understands.”

“I don’t see how the E.R.S. could collect tariff payments from a foreign manufacturer who is not also the U.S. importer of record,” Mr. Mojica added.

The question of who pays the tariff to the government is somewhat distinct from the issue of who ultimately bears the tariff’s costs. The importer can pass the cost of the tariff on to American consumers in the form of higher prices, or it could try to force its foreign factories to sell its goods more cheaply.

Every case is different, but several economic studies have found that American consumers mostly bore the brunt of Mr. Trump’s previous tariffs on China.

Some trade analysts say that the name “External Revenue Service” is an effort to disguise who really pays for tariffs.

Scott Lincicome, the vice president of economics and trade at the Cato Institute, which supports free trade, called the agency’s name “more branding than substance — and misleading branding at that.”

“Trump could call it the ‘Foreigners Pay the Tariffs Agency,’ and it still wouldn’t change the fact that Americans really are,” he said.

Five years since the pandemic began, workers have grown accustomed to a script. Their bosses make return-to-office plans, which then get shelved. And then shelved again.

In recent weeks, the calls to end remote work have come back with gusto, and with authority.

On Monday, President Trump signed an executive order requiring federal department heads to “terminate remote work arrangements” and require all federal workers to return to in-person work five days a week. He previewed the move in December when he said those federal workers who refused to go into the office were “going to be dismissed.”

Some chief executives, who have long been enthusiastic about ditching remote work, have also announced full return-to-office plans. Amazon, JPMorgan and AT&T told many employees they would have to be back in the office five days a week this year. Even in popular culture, the office is making a comeback, with “Babygirl” glamorizing the blouse wearing C.E.O., “Severance” returning for a new season probing corporate psychological drama, and buzzy newsletters like “Feed Me” declaring remote work “out.”

And some workers, who have come back to in-person work of their own volition, are eager to pick up their prepandemic work routines.

Two years ago, Ellen Harwick would have said she wanted to work remotely forever. Last fall, a switch flipped.

A marketing manager for an apparel brand in Bellingham, Wash., Ms. Harwick worked remotely for two weeks in Portugal while still working on Pacific time. Suddenly, she began to crave office chatter.

“Something just shifted for me,” said Ms. Harwick, 48. “Working from home was really novel for the first bit, and then I just felt isolated.” She is now back in the office five days a week.

But many proponents of remote work, who underscore the benefits it offers to people with caregiving responsibilities, voiced concern about flexibility evaporating entirely.

“It’s very challenging to find child care that allows you to be in the office 9 to 5,” said Sara Mauskopf, the chief executive and founder of Winnie, a start-up that connects families with child care providers. Her company is fully remote.

Amazon’s return to office began on Jan. 2, when the company instructed most workers to come in five days a week, up from the three days required as of May 2023. In some locations, the deadline has been postponed as the company reconfigures office space. Andy Jassy, the company’s chief executive, told employees in a memo that returning to the office would better allow workers to “invent, collaborate and be connected” to one another and to the company culture.

“Before the pandemic, it was not a given that folks could work remotely two days a week, and that will also be true moving forward,” Mr. Jassy wrote.

JPMorgan told employees that in-person work would support better mentorship and brainstorming. The company will start rolling out its return to office in March.

“We know that some of you prefer a hybrid schedule and respectfully understand that not everyone will agree with this decision,” JPMorgan wrote in a memo to employees. “We feel that now is the right time to solidify our full-time in-office approach.”

Many work force experts point out that executives have wanted people back in the office for a while, for the purposes of building culture and relationships. What has changed, they say, is that employers feel they have more leverage now that the labor market is not quite as tight as it was at the height of the Great Resignation, when there were more open jobs for the number of unemployed people.

“It becomes like another dimension of compensation — in a really tight labor market, employees get their way more, employers might not pressure them to come back because they might want to quit,” said Harry Holzer, an economist at Georgetown University. “In a labor market where there’s more slack, employers might be less worried about that.”

Sometimes a return-to-office push has less to do with building an office culture and more to do with cost. Nick Bloom, an economist at Stanford University who studies remote work and advises executives on hybrid arrangements, said he had seen some companies press employees to return to the office as a way to reduce head count, understanding that calling all workers back would encourage some to quit.

“The waning of the D.E.I. movement has made it a bit easier,” added Mr. Bloom, referencing the backlash to corporate diversity initiatives, and explaining that women and employees of color have tended to voice more support for remote work in surveys.

In spite of these high-profile efforts to get workers back five days a week, many other employers are holding on to a hybrid approach.

Data from a Stanford project tracking work-from-home rates shows that over one-quarter of paid full days in the United States are worked remotely. And about three-quarters of Americans whose jobs can be done remotely continue to work from home some of the time, according to Pew.

One of the reasons that hybrid work has remained so sticky is that workers have made clear their preference for flexibility. Nearly half of remote workers surveyed by Pew said they would consider leaving their jobs if their employers no longer allowed them some remote flexibility. At Amazon, corporate workers staged a walkout in May 2023 protesting R.T.O. Some employers said they had no plans to change course from hybrid arrangements.

“We are committed to providing flexibility to the work force and believe the hybrid-flex approach allows teams to collaborate intentionally,” said Claire Borelli, the chief people officer at TIAA, an investment firm that called its employees back to the office three days a week in March 2022.

Some remote work stalwarts say that the policy has had no impact on productivity and that it has helped employee retention. When Yelp’s lease came up for renewal in 2021, the company decided to shift locations and sublease a smaller space from Salesforce. The company now allows employees to work fully remotely, bucking broader return-to-office trends.

“At this point, we almost drop the descriptor of remote work — it’s just the way we work,” said Carmen Amara, the company’s chief people officer.

Ms. Amara said any skepticism the company faced over its remote policy went away because of bottom-line results. The company reported record net revenue and profitability in the last quarter of 2024, as well as a 13 percent decrease in turnover since 2021.

But with big names like Amazon and JPMorgan returning to the office in full force, and with President Trump insisting that the federal work force do the same, the commercial real estate industry is tentatively optimistic, according to Ruth Colp-Haber, the chief executive of Wharton Property Advisors, a real estate brokerage.

Office occupancy is still shaky — a little over half of what it was prepandemic — according to Kastle, a workplace security firm whose “return-to-office” barometer has reflected the ups and downs of remote work since 2020. But that is up from what it was in 2022.

“These things take a while to work their way into the numbers, but there’s no question the momentum is on the positive side,” Ms. Colp-Haber said. “For a variety of reasons, one of them being the push by big companies to have five days a week back in the office, we’re seeing greater demand for office space.”