It's a timely reminder on why you should always read the fine print.

35-year-old Greg Kelly has been given less than twelve months to live, and as he fights against the cancer in his bile duct he's also fighting to get a payout of more than $200,000 from insurance company TAL.

However TAL has denied his claim because when Kelly took out his life insurance four years ago he failed to declare he'd been suffering from colitis, an inflammation of the large intestine, which (according to doctors) has nothing to do with cancer of the bile duct.

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According to Paul Watson from Maurice Blackburn lawyers "the last thing (Kelly) wants is to go through is a legal battle to pursue his rightful entitlement."

Too weak to work, and with TAL digging in its heels, Kelly is now worried he'll lose his family home north of Brisbane.

Peter Dodd can understand his frustration.

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He's taking on Allianz to get back more than $14,000 he paid for a cruise through Europe which he never got to take with his wife Heather.

Stomach cancer would claim her life in May, but Dodd's problems stem from the fact he took out his travel insurance the day after Heather visited her GP complaining of feeling unwell.

Even though the GP found "the symptoms were of quite an innocuous nature" she was referred to a specialist for further tests.

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Allianz argues this is evidence that Heather was suffering "a preexisting medical condition ... Albeit a condition for which your wife was not diagnosed with at the time".

"I think it is worth fighting because I didn't know anything, my doctor didn't know anything, and the whole thing is based on that," Dodd said.

Like a growing number of Australians, Dodd's taken his complaint to the Financial Ombudsman whose office says travel insurance ranks among the top four most complained about products in the domestic insurance industry.

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When it comes to insurance policies, Ingrid Just from consumer watchdog Choice says the devil is in the detail.

"So you're not caught out by preexisting medical conditions, look carefully through the fine print," Just advised.

"The last thing you want to happen is to find out that you really need that travel insurance but you're not covered because you've been stung by a preexisting medical condition."