(Bloomberg) -- The Trump administration said the first tariff refund payment is set to go out around May 11, even as thousands of US importers encounter issues with a new online portal designed to handle claims on the $166 billion in duties that were overturned by the Supreme Court.

Most Read from Bloomberg

• North Korea Confirms Suicide Rule for Soldiers Ukraine Captures

• UAE Quits OPEC as War Upends Oil Markets and Gulf Tensions Rise

• 80 Seconds of Big Tech Earnings Will Decide Stock Market’s Fate

• Trump Being ‘Humiliated’ in Iran Talks, German Leader Says

• Trump Tells Aides to Prep for Lengthy Hormuz Blockade, Report Says

About 21% of import entries subject to tariffs under the International Emergency Economic Powers Act, or IEEPA, have been accepted so far to have those duties removed through a new Customs and Border Protection process, which began last week, according to an order Tuesday by Judge Richard Eaton the US Court of International Trade.

Eaton, who is overseeing the refund process, said about 3% of IEEPA entries are in the refund stage of that process, which will culminate in electronic payments from the US Treasury. Eaton issued the order following a closed-door hearing in Manhattan. Another hearing is set for May 12.

The scramble for refunds started immediately after the Supreme Court ruled Feb. 20 that President Donald Trump unlawfully used IEEPA to impose tariffs on goods entering the country. The 6-3 decision didn’t address the question of refunds, leaving it to the lower courts to hash out.

Out of the 13.3 million import entries that have cleared an initial review since the portal went live on April 20, about 15% were then denied for failing “entry-specific validations” as of April 26, Brandon Lord, an executive director at Customs, said in a public filing with Eaton earlier on Tuesday.

Importers can seek to fix any errors and refile, Customs said. About 1.74 million approved entries are in the refund process, the US said. Businesses and individuals paid the contested tariffs on approximately 53 million entries, according to information shared earlier by the government.

Greg Husisian, a partner at Foley & Lardner representing companies seeking about $1 billion in IEEPA refunds, said glitches are expected given how quickly Customs developed the refund functionality through a system called Consolidated Administration and Processing of Entries, or CAPE.

“There is no deadline to submit a CAPE declaration, and if it is rejected, an importer can fix the error and resubmit,” Husisian said. “So while these errors might have an impact on the timing of a refund, they should not, in the end, result in the government picking up money for any importer that diligently follows up and corrects any errors that resulted in the CAPE submission being kicked back.”