For private boats on Lake Constance applies the simplified customs clearance, which has been issued by all three countries as a general agreement.
Personal checks will not take place as a rule, but of course, exceptions prove the rule, as always. Of course, all people in the border region have to have a valid identity document with them.
The goods on board must not be subject of import/export regulations. Otherwise the goods must be declared in a customs harbour.
If the boat was repaired, renovated or got new accessories in a foreign country, the import should be checked upfront with customs in the home country. A non-declaration may violate regulations and lead to significant penalties in such cases.
Landings with customs office (D) Öhningen-Oberstaad + Wangen + Hemmenhofen + Gaienhofen = announcements: +49-(0)7731-143190
Landings with customs office (D) Radolfzell + Insel Reichenau + Konstanz Hafen + Mainau = announcements +49-(0)7531-124260
Landings with customs office (D) Überlingen + Meersburg + Friedrichshafen + Langenargen = announcements +49-(0)7541-3887310
Landing with customs office (D) Lindau = announcements +49-(0)8382-277530
Landings with custom office (A) Seehafen Bregenz = announcements +43-(0)5574-699569009
Landing with customs office (A) Hard = announcements +43-(0)5574-699569006
Landings with custom office (CH) Romanshorn = announcements +41-(0)71-4667380
All information to the best of our knowledge but without any guarantee.