Many people may take their birth certificate, or similar official papers, for granted - hidden in a drawer and rarely seeing the light of day - but for those without one, it can lead to a shadow life or an uncertain existence.
This is thought to affect millions of people around the world, described as stateless, and 25-year-old South African Arnold Ncube is one of those.
Because he has no state-issued documents, washing cars in the backstreets of Thembisa township near Johannesburg is one of the few ways he can make a living.
He was born in Johannesburg and his father is South African, qualifying him for citizenship here. But when he tried to register for secondary school, he realised he didn't have a birth certificate.
Having been abandoned by his parents - his dad left before he was born and his mum when he was 14 - he could not prove his status.
It's a painful thing, he says. You're basically invisible. You don't exist. It's like you're living in the shadows. You don't have a bank account, you can't apply for a decent job that you can earn a living with.
Arnold is one of at least an estimated 10,000 stateless people living in South Africa who, despite being born here, are struggling to prove their nationality and access public services.
Statelessness is caused by many factors, including administrative barriers and poor record-keeping. As a result the real number of stateless people is hard to gauge in many parts of the world.
There's an estimated 4.5 million stateless people around the world. Some experts believe the figure could even be as high as 15 million.
