The 31 year-old man believed his claim for a Disability Support Pension in 2003 for psychotic depression, severe repetitive rituals, frequent anxiety attacks and auditory hallucinations and paranoia had been turned down.

However, further inquires following another DSP application in 2007, on his doctor's advice, he discovered Centrelink had lost his original claim and application.

Represented by Social Security Rights Victoria, he has been back paid the difference in entitlements and awarded about $10,800 from the Department of Finance.

The Moe man, who wished to remain anonymous for privacy reasons, said it took 18 months to receive compensation.

"I am very happy with the result and it was very hard waiting all that time for the money," he said.

"It did take a long time, but it was very good to get back-paid for all that time."

Social Security Rights Victoria coordinator Peter Horbury said documents often got lost in the Centrelink "vortex".

"That's why it's important to always double check, question them, appeal decisions and come to us for advice," Mr Horbury said.

In the 2010-11 SSRV provided advice to 1146 clients, about five per cent of those were related to lost Centrelink forms.

For more information on Social Security Rights Victoria's free support and advice to people experiencing issues with Centrelink, phone 9416 1111.