Story highlights Secret Service officers were observed dealing with British reporters

In the United Kingdom, the date is recorded by the day of the month followed by the month itself

Washington (CNN) Some British reporters said Friday they were unable or delayed in entering the White House to cover their prime minister's visit to the White House.

Secret Service officers were observed dealing with British reporters upset that their birth dates did not match what had been recorded by security personnel. In the United Kingdom, the date is recorded by the day of the month followed by the month itself, unlike in the United States.

"British press corp is locked outside the White House because our birthdates were submitted in UK format and secret service don't get it," one British reporter from BuzzFeed, Jim Waterson, tweeted. He later added: "Those of us born after the 12th day of the month have been let through."

Moments before British Prime Minister Theresa May's motorcade entered onto White House grounds, members of the British press remained outside the North West gates, waiting for the Secret Service to tell them they were good to go.

One British journalist, presenting his UK passport, could be seen asking an officer if he was cleared, with the officer telling him that his birthday was still reversed in the system. He had to continue waiting among a handful of others.