The United States Customs and Border Protection alerted users about a glitch in the system used to exempt freight shippers from tariffs recently imposed on foreign countries, according to CNBC.

The exemptions apply to all freighters already on the way to US ports, including ones sailing to the country from China. It also applies to all countries under the 90-day duty pause previously instituted by US President Donald Trump. In its alert, US Customs clarified that the glitch was related to the entry code used by US shippers to exempt their cargo from tariffs not working properly. Customs instructed filers "to transmit cargo release separately and follow up with the summary filing when resolved."

As per the currently enforced "on water" clause, the US will not be collecting tariffs on cargo on freight sailing to the US and which has been on the water before the government announced new levies on April 5, 9, and 10.