The world’s largest package delivery company is stepping-up security measures for customers mailing packages. The move comes after explosives were discovered on a UPS plane over a month ago.

In late October, a UPS cargo plane bound for Chicago was stopped in London after explosives in a printer cartridge were discovered. The package was later traced to a company retail location in Yemen.

UPS spokeswoman Susan Rosenberg says customers now will be required to show photo identification at retail locations worldwide, like The UPS Store and Mail Boxes Etc.

“In the process of reviewing security, we saw that this was a measure that we could take and extend across all of the retail channels.”

Rosenberg says previously, ID was required only at the company’s service center locations.

Atlanta-based UPS is in the midst of the busy holiday season, where it expects to move 430-million packages.

Tags: Atlanta, UPS, explosives, package delivery, security