Over the years we came across several issues / problems travelling with kids:
1) once we were going with our girl to Uruguay with Buquebus. Both parents present, but my wife kept her name when we got married. So the child’s surname matches with the father’s but not with her mother’s. Luckily, in her European passport both parents’ names are mentioned. So they let us go finally. However, to avoid the risk always carry the birth certificate even if travelling with both parents
2) Then i travelled with my daughter alone to Europe. I knew about the issue of travelling with a child alone, so we got an official document from an escribano, allowing her to travel either with her father or mother. My daughter had a European passport, but only a DNI and not an Argentinian passport. Until that moment she was always travelling with her European passport. In this document there was a reference to her DNI. Apparently as an Argentinian citizen you need to travel abroad with an Argentinian passport. I wasn’t aware of that. We were rejected to leave by the border official at Ezeiza, and his supervisor confirmed this.
3) after the episode in 2) we obviously decided to get a an Argentinian passport for the daughter, and decided also to get a new carta de identidad. Before receiving the new documents, we decided to take another trip to Colonia. However, the carta de identidad (DNI) wasn’t valid any longer (once you apply for new document, you basically can’t leave the country until receiving the new ones). Also here we got a strict NO.
Ad 2) and 3): in both cases we pushed the cry button of the kid (“we can’t travel and see your Granny” … ), and when Argentinians have a weak point then it is clearly a crying kid. In both cases things escalated to the next higher level and in both cases they made an “excepción”…. That’s also Argentina
However, I clearly wouldn’t rely on this as a strategy.
We did the document for travelling with kids at the Escribano Ferrari in Microcentro (Peru 79). But any Escribano can do that i suppose.