The planned codeshare between Frontier Airlines and Volaris has been given the green light by the US Department of Transportation.

The two airlines first reached an agreement on the deal in January. Volaris estimates that its passengers will be able to reach about 20 more US cities than they can today, while Frontier passengers will gain access to Volaris’ network of 40 destinations in Mexico.

Speaking at the time the codeshare was agreed, Volaris chief executive Enrique Beltranena said: “We estimate that our partnership will add around 20 new destinations to our network and 80 new routes between both Mexico and the United States.”

Volaris currently serves 24 destinations in the US and 40 in Mexico, of which 21 coincide with Frontier destinations in both countries. The codeshare agreement greatly enhances the potential for connecting itineraries.

This agreement will allow Frontier to place and sell tickets with its code (F9) on Volaris operated flights and for Volaris to place its code (Y4) on Frontier operated flights.

Volaris currently offers more than 323 daily flights on routes that connect 40 cities in Mexico and 28 cities in the US and Central America. Frontier flies to 80 destinations in the US, Canada, Dominican Republic and Mexico on more than 320 daily flights.

Both carriers form part of private equity firm Indigo Partners’ portfolio of airlines and recently boosted their order books as part of a deal for 430 additional Airbus A320neo Family aircraft. Volaris will receive 46 A320neos and 34 A321neos, while Frontier will receive 100 A320neos and 34 A321neos.