Here are six things you should never do when crossing from one country to another.

Border crossings can range from boring to nerve-wracking, depending on your destination. When you’re traveling between two countries, there are certain things you should never do, lest you wind up delayed, detained, or even deported.

1. Forget to check your stamp

Border agents are human too, and they can make mistakes. Before you step away from the counter, quickly check your passport to make sure they have given you the correct arrival (or departure) stamp with the current date. If something was done incorrectly, it will be much more difficult to fix later on.

2. Lie

Afraid a past arrest or criminal conviction will prevent you from entering the country? Lying about it isn’t going to help. Border agents generally have access to records and databases from other countries, so they will be able to quickly see if you aren’t telling the truth in response to a question. Falsifying information can get you banned from the country entirely for a designated period of time or even life.

3. Be rude

Answering a round of seemingly endless questions at a border can be very frustrating. However, being rude or angry definitely won’t help matters. Remain patient and be exceedingly polite in all your interactions with border agents; they have a lot of discretion, including the ability to ban you from entering.

4. Take photos

As you pass through border control in most countries, you’re likely to see big signs warning against taking photos or videos. Heed this directive, as snapping a picture (even if it’s just of yourself entering the country) can land you in trouble. Further, border control is considered a high-security area, and taking pictures/videos can make you look suspicious and bring unwarranted attention to your traveling party.

5. Joke around

Jokes about smuggling drugs or never leaving the country may be funny among your friends, but if border agents overhear these comments, you’ll definitely be in trouble. Just like when going through airport security, staff at borders have to take all comments at face value , no matter how obvious you think it is that you’re joking.

6. Be unprepared

Always do your research as to what you’ll need to enter your destination. Some countries only accept payments for visas or other fees in cash (in the local currency), so make sure you’ll have the correct amount on hand. Consult the embassy website for the country you’re visiting to determine if you’ll need a visa, proof of vaccination, or any other requirements for entry. You don’t want to be put back on a plane home after getting off a long flight just because you didn’t have the right documents.

Twist’s Take: Don’t risk being delayed, detained, or even deported; refrain from doing these six things when crossing an international border.