using static System.Console;

​

using Newtonsoft.Json;

​

#nullable enable

var json = "{ \"AccountIdentifier\":{ \"accountId\":null, \"iban\":null, \"bban\":\"Identifier45cc31dd-d2dc-4957-90e9-0cc1748fc327\" }}";

var dc = JsonConvert.DeserializeObject<ThingThatHasAccountIdentifiers>(json);

​

WriteLine(dc);

WriteLine(dc.AccountIdentifier.Bban);

​

public class ThingThatHasAccountIdentifiers

{

    public AccountIdentifiersWithMissingAccountId AccountIdentifier { get; set; } =  null;

}

​

public class AccountIdentifiersWithMissingAccountId

{

    public string? Iban { get; set; }

    public string? Bban { get; set; }

}