By Valentine Hilaire, Gonzalo Soto and Carolina Millán Shein says a delay in renewing a key Mexican shipping permit is putting its business in the country at risk.

The online fashion retailer’s warning is part of growing alarm in the industry as 11 logistics operators have started losing their authorizations to clear large volumes of lower-value shipments.

The permits are part of the nation’s so-called T1 framework that streamlines couriers’ ability to import shipments worth up to $2,500 per recipient, according to Mexico’s tax authority. The rules have helped fuel rapid growth in Mexico’s e-commerce.

Two T1 permits have already expired in October, including that of Conejo Corriendo, a local subsidiary of China’s J&T Global Express and a provider for popular online retailers Temu and AliExpress. Another firm, Welldex Trading, also lost its authorization.

The permits of DHL, UPS and FedEx are set to expire Dec. 2, while that of local shipping firm Estafeta will expire Dec. 22.

Shein’s communications director, Patrick Lassauzet, said “a reduction in authorized operating capacity under the T1 framework can quickly turn into a real problem for consumers.”He pointed to a disruption earlier this year at one of Shein’s logistics providers that impacted about 200,000 orders. The company was forced to issue refunds following prolonged delivery delays, he said in an email. Lassauzet didn’t specify which shipping companies Shein works with.

Shein, which went public earlier this year in a $1.7 billion Hong Kong offering, said it supports compliance with customs rules, but called for a “timely and transparent resolution.”Mexican Senator Luis Donaldo Colosio, a member of the opposition Movimiento Ciudadano party, estimates that allowing the permits to expire could cost the government 33 billion pesos ($1.8 billion) in lost tariff revenue next year. It would also put more than 66,000 jobs at risk, he added.

Mexico’s customs council, which is the entity responsible for the renewals, hasn’t publicly disclosed the government’s strategy or said whether it will renew the permits. The council includes officials from the Finance Ministry, the National Customs Agency, the tax agency and the Ministry of Anti-Corruption and Good Governance.

In response to questions from Bloomberg, the council said that all permits are published in a timely fashion after being granted, and decisions to extend or authorize permits are made during monthly meetings. It declined to say when the last meeting was held or when the next one would be.

Conejo Corriendo, DHL, and FedEx didn’t reply to requests for comment. UPS said it’s committed to following official requirements to ensure a first-class service, without providing further detail. Estafeta declined to comment.

Letting the authorizations expire “would be irresponsible and could create chaos” for e-commerce platforms, logistics companies and customs authorities, said Ignacio Casas, a foreign-trade consultant and professor at the Tecnológico de Monterrey university. It could potentially force large volumes of shipments to be processed individually, he said.

The council, which only took over customs oversight this year, may still be working out how to handle renewals, Casas said. Authorities may also be seeking greater transparency and tighter controls to counter abuse that ocurred under the T1 rules, he added, such as companies understating the value of shipments.

In the meantime, companies that sell imported goods face greater uncertainty. To protect the domestic industry, the government has already raised taxes on apparel from countries such as China that don’t have trade agreements with Mexico.

The delay represents another headache for Shein, which was hurt by the end of the US de minimis trade exemption that allowed imports worth less than $800 to enter without being charged duties. Shein, which also operates an online marketplace for third-party vendors in Mexico, may be looking to sell more in Latin America to offset a decline in the US.

Colosio urged the customs council to meet and resolve pending approvals for next year. He also raised concern about the potential impact to Felipe Ángeles International Airport — a new airport serving the Mexico City metropolitan area that has emerged as a hub for cargo and e-commerce shipments.