Train from Florence to London to skip my flight out of Milan

1) If you skip the Milan to London leg of your journey, the rest will be cancelled.

2) The train from Florence to London will take 20+ hours and include at least 3 changes.

You would be better off seeing if the airline will let you fly out of a different airport that Milan such as Rome which is less than 3 hours from Florence. You could also check out Geneva or Zurich.

For trains look at the DB Bahn website. https://www.bahn.com/en/view/index.shtml

My problem is trantalia app I can never get to work

Are you:

• using Italian stations names? It's Firenze SM Novella and Parigi
• using the real date format? It's dd/MM/yyyy
• using this app: https://apps.apple.com/it/app/trenitalia/id331050847
• aware that Trenitalia.com does not display competitors' trains
• aware that Trenitalia.com does not display trains entirely running between foreign countries (like the train from Paris to London)

Anyway, you must take an Italian train to Torino Porta Susa station and a French one from Torino Porta Susa to Paris. In Paris I think you'll have to get to Paris North, the station used by the trains to London.

Have you tried changing you ticket to fly to London from Florence, even with change fees it will probably be cheaper than the cost by train and less wearing than a long train journey before a transatlantic flight.

You have to change your plane ticket to a new one if you change your outbound airport. If British Air cancels the outbound flight on its own that would make it easier/ less costly. If you change it beforehand, then you'll be liable for the change fees unless British Air gives reprieve (which may very well be the case, it's worth checking).

British Airways may be canceling some flights from Venice and MIlan, but the dates I can find on theiir website are only up through March 9. Call them and see what you can do.

The really is no such thing as a train from Florence to London. Really a train to Paris and then to London. That is really not an option or at least a very workable option. And, if you skip the first leg, without permission, then the rest of the ticket will be cancelled since you are a no-show in Milan.