Spain's national carrier Iberia has upgraded two of its routes to Croatia from seasonal to year-round operations. Services from Madrid to both Zagreb and Dubrovnik will continue past the summer. Flights between the Spanish and Croatian capitals will be maintained twice per week with an Airbus A319 aircraft, each Tuesday and Saturday, during the 2018/19 winter season, which begins on October 28. Similarly, services to Dubrovnik will run twice weekly, each Wednesday and Saturday. Iberia faces no competition on the two routes. "During the winter months there'll be two weekly flights between Madrid, Zagreb and Dubrovnik, with excellent connections from other airports in our network. These new additions to our programme will reinforce our presence in Croatia, not only for point-to-point flights but for long haul connections as well", Iberia said in a statement.

The Spanish airline has boosted both frequencies and capacity to Croatia this summer. The carrier will maintain up to eight weekly flights from Madrid to the Croatian capital, an increase from five weekly last year. It also brought forward the resumption of the service by a month to early May. Furthermore, Iberia is adding four weekly flights to Dubrovnik, resulting in double daily operations during the peak summer months, while Split will also benefit with daily services to be maintained from Madrid this year, up from three per week in 2017. In a statement to EX-YU Aviation News, the airline said, "We will be offering 48% more seats to Dubrovnik in the summer of 2018 compared to last year. To Zagreb, we are offering 79% more seats this summer than the previous one. Finally, capacity to Split will grow by 189% in 2018".

Iberia's low cost subsidiary, Vueling Airlines, has also strengthened its operations to Croatia this year. The carrier has added two weekly services between Barcelona and Split, for a total of nine per week, and an extra flight between Rome and Split, totalling thirteen weekly operations. The airline will also continue to maintain its year-round flights from Barcelona and Rome to Dubrovnik, and launch operations from Vienna to the sea side city. Furthermore, it will run seasonal services from Barcelona and Rome to Zadar. Finally, Vueling also maintains operations from Florence to Split and Barcelona to Zagreb.