Everyone has the right to a nationality, according to the UN Universal Declaration of Human Rights, but an estimated 11 million people across the world do not enjoy such status.
In the first of a series, we look at Thailand, which has one of the largest stateless populations in the world.
Five years ago, the Thai police arrested Afang Chue Mua and threatened to deport her, to send her to back to Myanmar.
The UN defines a stateless person as someone who is not a national of any state under its laws.
No refugee status
No ability to claim asylum
Stateless people often have minimal, if any, access to basic rights such as education and healthcare.
The problem is that she is not from Myanmar. She was born in Thailand and so were her parents.
They are members of an ethnic minority called the Akha, one of seven hill tribes that live in northern Thailand, near the border with Myanmar and Laos.
Afang told Al Jazeera: "We belong to this country. We have no doubt about our nationality - we are Thai."
Thailand's small hill tribes are one of its biggest tourist attractions.
The tribes bring in millions of dollars each year, but half of them – nearly one million people - still are not accepted as citizens.
In fact, their children, born and raised in Thailand, are treated like illegal immigrants, refugees in their own country. They are denied equal access to schooling, to medical care.
The Akha can not get good jobs. Without proper documents, they can not travel, even within Thailand and they are vulnerable to arrest and deportation to countries they have never even seen.
There are a quarter-million refugees in Thailand from Myanmar and Laos, as well as from China, Vietnam and Cambodia.
Most of them belong to the same ethnic minority groups as the hill tribes in Thailand, so there is some room for confusion.
Kumpol, a Thai official from the government registration unit in Chiang Rai, told Al Jazeera: "Fifty per cent of the citizenship applications we receive are fraudulent."
But Somchart Piphatraradon, who runs a hill tribe citizenship project, says the problems run deeper.
Piphatraradon, of the Mirror foundation, said: "There's no clear cut government policy to solve this problem because they think it's a small matter.
"There's also prejudice towards ethnic minorities. And there's corruption. Citizenship is a source of money for those with power."
|Afang now works to educate hill tribe villages|
about applying for Thai citizenship
Afang, now an ethnic minority rights activist, has applied for Thai citizenship and she is working to help others get it too. She visits hill tribe villages to explain the procedure.
She said: "I used to cry a lot, like when I was in jail and they called me an illegal immigrant. I'm not an illegal immigrant."
"I used to get angry because I was young and didn't know the law. Now, I know the law, I know what to do."
She says she will always be Akha, but the Akha do not have their own country, so she needs to be Thai.
Source: Al Jazeera