Kees Smit has extended his contract by two more years until 2030. Regarding his extension, Smit said that he feels very comfortable at the club and there is still a lot to learn. Sporting director Niels van Duinen explained that a lot has been said and written about Kees. Van Duinen called him an incredibly great talent, but stated the strength of the contract extension is primarily due to the feeling that Smit has at AZ. According to the sporting director, Smit really wants to build and achieve something at the club, which he feels is something not often seen in today’s football.

According to Voetbal International, Kees Smit and AZ are nearing an agreement on a contract extension until mid-2030. Smit's current contract is valid until 2028, and talks about an improved and extended contract have entered a new phase. It is expected that Smit will sign the new contract soon if the final details are agreed upon.

Niels van Duinen stated in conversation with Voetbal International that talks are ongoing about a longer stay for 20-year-old Dutch central midfielder Kees Smit at AZ. After a cup win, Kees Smit told Rodi Media that he might stay another year at AZ. Van Duinen said that Kees has spoken about this himself and that he has read that too, adding that he sees that as something positive and that they have already talked to him about this. Smit is under contract with AZ for two more years. Van Duinen expressed a desire to extend that contract. The Netherlands international has one cap for his country and made 26 appearances in the 2025/2026 Eredivisie season, scoring 3 goals and providing 3 assists. According to Transfermarkt, Smit has a current market value of €25.00m. He has been linked with several clubs, including FC Barcelona, Real Madrid, and Liverpool.