On May 15, Delta began non-stop service from JFK to Manchester, England, and Dublin, Ireland, using Boeing 767 400s. The airline says that all 285 seats will be sold as economy, and stated in a press release that “premium and elite customers will be eligible for First Class upgrades at time of departure based on their standing in the Delta SkyMiles program and fare class.” That’s because these planes, taken from other routes, have a domestically configured First Class cabin—not good enough to command a premium international fare.

But don’t wait until departure. Our research shows that a Delta elite member can confirm a First Class seat at ticketing just by having a travel agent enter the SkyMiles number in the reservation beforehand—and with the lowest fares. That’s just $228 round-trip to Manchester, $572 to Dublin.

For non-elites, we found that booking a B fare, starting at $1,298 round-trip, would open up the front cabin at time of ticketing on the Dublin route. On the Manchester route, the lowest B fare eligible for an upgrade at time of ticketing is $1,584.