My boyfriend and I are traveling to Budapest, with a flight change at the Frankfurt airport. Do we have to go through customs at that airport, then again at Budapest, or is it only when you are actually leaving the airport that you have to go through customs? Thanks for the patience with my stream of possibly silly questions.

You should only have to go through Immigration in Frankfurt and you will go through customs in Budapest.

Correct me if I'm wrong but although Hungary is now part of the eu, it is not a signatory of the Schengen agreement as far as border controls are concerned.

Therefore you will not go through immigration in Frankfurt but rather immigration and customs only upon arrival in Budapest.

xyz123- I never thought of that - you just may be correct in this instance. Thank you for pointing that out - I would hate to give incorrect information.

Thank you! I am just trying to make sure I know what is going on when we get there- nothing worse than starting out a trip lost in a foreign airport.

>although Hungary is now part of the eu, it is not a signatory of the Schengen agreement as far as border controls are concerned.

Hungary is a member of Schengen accord since late 2007 already.

Land and sea border control was abolished from 21 Dec 2007, and from 30 March 2008 internal border controls at airports have been lifted.
So you go through passport check at Frankfurt as your entry point for Schengen, and customs check on arrival at Budapest, but as you are flying on an internal Schengen flight, there will be a minimum formality.