US citizens are not required by the law to always carry with them a proof of US citizenship. However, they need to hold a federal document to prove that they are US citizens. US citizenship grants the citizens a lot of privileges and the citizens will also be able to travel abroad hassle free and US citizens need not obtain visas to travel to many foreign countries. But to obtain all these citizenship benefits, it is mandatory to hold a document to prove that you are a US citizen.
Few government issued documents may be used to demonstrate that you are US citizen. You may use your birth certificate, US citizenship certificate, naturalization certificate or your US passport, to prove that you are a citizen of the country.
People who were born within the United States, need not file applications and obtain any documents to prove that they are citizens as the birth certificates that were issued to them when they were born, can be used as a proof of their US citizenship and they are US citizens by birth.
Individuals who are not US citizens by birth may acquire or derive citizenship from their parents, if their parents are native or naturalized US citizens. If you did not derive or acquire American citizenship and if you were born in a foreign country, you can become a citizen through the formal naturalization process. However, all the foreign nationals cannot become naturalized US citizens and they need to meet few prerequisites and must be above 18, to file their US citizenship applications. Foreign nationals who obtain US citizenship through naturalization may use their naturalization certificates to demonstrate that they are American citizens.
How to prove that you are a US citizen if you were born to US Citizens abroad?
You will still be a US citizen, if you were born in a foreign country, if either one of your parents was a US citizen, when you were born. In such cases, you may derive citizenship from your parent who was a US citizen. However, every individual who was born abroad to US citizens may not become eligible for citizenship and the law that was in effect when you were born will help the officers to decide whether you are eligible for citizenship or not.
Immigration laws are not the same and the laws are being changed and according to the immigration laws, for a person to derive citizenship from his parents, either his father or his mother must have been a US citizen. Similarly, you must live legally with your parent who is a US citizen to get a citizenship certificate.
You may also acquire citizenship from your parents if your parents had applied for naturalization and obtained citizenship before you turned 18 and in such cases, you may file the USCIS Form N-600 and get your US citizenship certificate. People who acquire or derive citizenship will become eligible for US passports and will be granted benefits that are granted to native US citizens.
What if your birth was registered in a foreign country?
If you were born on foreign soil to US citizens and if your birth was registered before your 5th birthday, in a US Consulate, you may use your consular birth registration certificate as a proof of American citizenship. If your birth was not registered or if that certificate was misplaced, you need to apply for a US citizenship certificate on Form N-565 or you will have to apply for a US passport.
What documents should I use to prove US citizenship if I am a naturalized US citizen?
If you were not born within America, you may become a citizen though naturalization. If your application is approved, you will be issued a naturalization certificate, that can be used as a proof of your citizenship. If you tend to lose your naturalization certificate, you will have to file Form N-565 and obtain a copy of your naturalization certificate. You can also get a US passport after becoming a naturalized US citizen.