Graduate student Nicole Lobo moved back to the US in late August after a year in the UK, shipping 10 boxes of possessions back home to Philadelphia that she expected to arrive within a few days.

Six weeks later, she is still waiting for the shipment – and fears it is lost, destroyed by UPS as the company struggles to handle a flood of packages facing new customs and tariff rules.

“It’s been horrific,” says the 28-year-old, who was notified last month that her boxes would be disposed of, leaving her to make frantic phone calls and send emails to try to head off the outcome.

It’s an ordeal facing many UPS customers since the Trump administration in late August stopped allowing parcels worth less than $800 to enter the US without inspection, taxes or tariffs.

The decision abruptly made an estimated 4 million packages each day subject to new, more onerous processing and documentation rules.

As the influx leads to longer processing times and higher, sometimes unexpected, costs across the industry, some customers of UPS like Nicole, say they fear their packages have been lost in the backlog.

“It’s beyond comprehension to me,” says Janani Mohan, a 29-year-old engineer living in Michigan, who has also spent hours on hold and sent repeated emails since a tracking alert listed a box sent by her parents in India as set for disposal.

The parcel held her wedding dress, which had also been worn by her mother, an heirloom sari from her grandmother and wedding photos, among other items.

“I literally cried to them on the phone,” she says. “Everything in there is very close to my heart.”

Oregon-based Mizuba Tea Co, which has used UPS for more than a decade to import matcha from Japan, has five shipments together worth more than $100,000 held up in processing.

The firm has received conflicting alerts about their status, including some saying the items were set for disposal.

“My whole team is basically on scan watch,” says Lauren Purvis, who runs the business with her family and is now starting to worry about running out of inventory if the limbo continues.

“It’s just clear to us that the current importing systems were not prepared to handle the sheer amount of volume and paperwork.”

Importers typically have 10 days after goods enter the US to submit documentation about the goods, pay tariffs and other fees, allowing the package to go to its recipient.

But the Trump administration’s rapid changes to tariff rules have made it increasingly difficult to meet customs deadlines requirements, say shipping companies like FedEx and UPS, which offer customs services and often act as importers of record.

For example, businesses are now responsible for paying tariffs on any steel or aluminium contained in a product , and in many cases vouching for its country of origin – information that many businesses, let alone their shipping companies, do not know.

“Because of changes to US import regulations, we are seeing many packages that are unable to clear customs due to missing or incomplete information about the shipment required for customs clearance,” a UPS spokeswoman said.

While acknowledging longer shipping times, the company said it was still successfully clearing more than 90% of international packages within a day of arrival.

The spokeswoman said its policy was to contact customers three times before moving to dispose of a package.

But seven people interviewed by the BBC, including several businesses responsible for shipping the items, said they had received no word from UPS about issues before seeing the tracking alert that their package would be trashed.

FedEx, another major player in the industry, said it does not typically destroy packages, unless directed to do so by the shipper.

Nicole, the graduate student, says she has been asked to supply more information about her items, which she did promptly in early September.

She did not hear more until seeing the notice about disposal in late September. After the BBC enquired about her package, the tracking information was updated for the first time in weeks to say it was “on the way”, raising her hopes.

Likewise, Janani says the company reached out last week, after the BBC got in touch, for a few more documents and her package now appears to have cleared customs.

But for businesses, the chaos has already had real costs.

Swedish candy exporter Swedish Candy Land says more than 700 packages it sent via UPS to customers in the US in the first few weeks of September have been held up.

Co-founder Tobias Johansson says the business switched to FedEx after becoming aware of the problem and its shipments were now arriving without incident, although the process took a few days longer than before .

But the lost packages, some of which have been reported destroyed, have cost the firm roughly $50,000 in refunds, not including the expenses they incurred in shipping and brokerage fees.

“That was a big hit for us and we haven’t gotten any answers yet for anything,” says Mr Johansson.

Experts say the ripple effects are being felt across the supply chain, even on businesses, like Mizuba, that were not bringing in shipments using the $800 exemption from tariffs, known as de minimis.

“This can be felt pretty much across the board,” says Bernie Hart, vice president of business development at Flexport, a logistics and customs business.

In a call with financial analysts last month, FedEx executives said it had been a “very stressful period” for its customers, especially smaller players.

“That is a big headwind,” chief executive Raj Subramanian said, warning that changes to the trade environment would likely lead to a $1bn hit this year, including $300m in additional expenses as the firm hires and faces other costs related to the new rules.

But John Pickel, vice president of supply chain policy for the National Foreign Trade Council, which represents many shipping firms, fears the issues may get worse before they get better.

Overall trade volumes last month were lower than is typical, in part because many businesses rushed goods into the US early to beat tariffs.

“There’s always been this prevailing thought that companies will figure it out,” he says. “What we’ve seen is that is much harder than anyone anticipated.”