The factory keyless entry system for 2014 Mazda 3 vehicles equipped with push-button start uses one of two “Smart Key” remotes. Both remotes have FCC ID WAZSKE13D01.
There is a 3-button remote with lock, unlock and panic buttons. This remote was used on 2014 Mazda 3 5-door vehicles and on 2013-2015 Mazda CX-5 SUVs. The current Mazda part number for this part is KDY3-67-5DY. The Remotes Unlimited part number is 084-6340. See the part at this link.
There also is a 4-button remote with lock, unlock, trunk and panic buttons. This remote was used on 2014 Mazda 3 4-door sedans. The current Mazda part number for this part is GJY9-67-5DY. The Remotes Unlimited part number is 084-6545. See the part at this link.
Both of these parts are sold without a blank emergency key and require dealership programming with a scan tool.