customize [customized, customizing, customizes](alter according to preferences) verb [UK: ˈkə.stə.ˌmaɪz] [US: ˈkə.stə.ˌmaɪz]
personalize [personalized, personalizing, personalizes](to adapt to an individual) verb [UK: ˈpɜː.sə.nə.laɪz] [US: ˈpɝː.sə.nə.ˌlaɪz]I think it would be difficult to personalize every wedding invitation. = Creo que sería difícil personalizar cada invitación de boda.