Taylor Swift and Travis Kelce's Wedding Celebration Invitations Watermarked to Prevent Leaks

Taylor Swift and Travis Kelce have taken extraordinary measures to make sure their wedding celebration invite doesn't leak ... TMZ has learned.

Sources with direct knowledge tell TMZ ... every invitation is individually watermarked with the guest's first and last name repeated throughout the invite, a security measure designed to identify anyone who leaks it online.

We're told invitations began going out in early spring, with many guests receiving them around April.

Our sources say if a guest were to photograph the invitation and post it publicly, Taylor and Travis would be able to trace it back to the specific attendee whose name appears throughout the invite.

The couple is also keeping the celebration's location tightly guarded. We're told the invitation doesn't mention Madison Square Garden at all. Instead, it simply lists New York City as the location and July 3 as the date, withholding the exact venue from guests' invitations.

The added precautions reflect the scale of the event. As TMZ first reported, between 1,100 and 1,200 guests are expected to attend the celebration, making privacy and security a top priority.

We also reported a permit was filed with New York City to close streets surrounding Madison Square Garden from July 2 through midday July 4 for festivities centered around a July 3 event.

As we've reported, Stevie Nicks and Tim McGraw are expected to perform during the event, and our sources tell us Paul McCartney's name has also been floated as a potential performer.

With individually traceable invitations, strict security measures, and one of the biggest celebrity guest lists in recent memory, Taylor and Travis are doing everything possible to keep details of their celebration under wraps until the big day.