I am a citizen from a non-Schengen country but I do not require a visa to enter the Schengen region. If I travel to a Schengen country ( which I think will be Romania; too many uncertainties still) and then travel to Spain or other Schengen region country, will I still have to go through customs check? I am looking for a way of simplifying my trip by maybe just taking a train or traveling by car. There is a related post : Do I need a multiple-entry visa for an intra-Schengen layover? But it does not seen to address my question.
When traveling from Schengen EU country to Schengen EU country by direct border you will not see customs, if you fly between Schengen EU countries you might see customs but can ignore them by going through an EU lane or nothing to declare.
For the non EU Schengen countries there is likely to be a customs check but no passport stamp, they might want to see your passport but when you are legally in the Schengen area, that is no problem.
At or near all borders they can check your passport although they will not stamp.
EU non-Schengen countries will check and stamp your passport. But when traveling within the EU there will be no customs check.
Be sure you know which countries are in the 'no passport check' Schengen area.
In this Wikipedia page you will find a clear map and a lot of text explaining which countries are in Schengen.
Romania is not yet in Schengen.
Schengen is an area of free circulation for people, so it removes systematic border controls of IDs.
Customs are for goods, not people. Most customs checks are removed within the EU.
Even though most Schengen countries are in the EU and most EU countries are in Schengen, there are exceptions both ways:
- some EU countries are not in Schengen, like Ireland or Romania
- some Schengen countries are not in the EU, like Switzerland.
This means that there will be ID checks between Romania and the countries in the Schengen Area. There should be no systematic ID checks when travelling between countries in the Schengen Area, but there are exceptions (related to the migrant crisis and terrorism risks), and there can be random checks, at the border or anywhere else, really.
You must always carry ID at least when crossing borders, ideally always, especially if you look like you could come from a country which is considered a high risk of illegal immigration.
There will be no customs checks between Romania and other EU countries, but you may find some between other Schengen countries, like Switzerland.
Note that even within the EU there are a few restrictions on what can be transported across borders, like cigarettes or alcohol, due to specific tax regimes.
The internal borders of the Schengen area have no systematic immigration checks. There may be random spot checks, but if so you will be asked. It is a very good idea to carry your passport.
(Some countries do not conduct checks at the border, but they run random checks in the border area. Legally it might be a difference if you are asked for your papers as you step over the line or 100 metres onward, for practical purposes it isn't.)
There are still certain customs limitations. You can carry goods for personal use, but over certain limits there will be a legal assumption that it is no longer personal. Again no regular checks, but failure to declare excess goods may be punished.
Also note that Switzerland is Schengen but not EU, check the conditions which apply.