Up to 12,000 former Gurkhas may apply for UK residency in the next three years and new arrivals will typically need charities to provide them with money and accommodation, according to the Army Benevolent Fund.
"They will arrive from an aircraft, they´ll probably have two suitcases and no more. They´re going to need everything to set up home," the charity´s director of welfare Paul Cummings told the BBC.
It was "an issue of grave concern" that some of those arriving seemed to be so ill prepared for life in Britain, he said.
A dozen families had already approached his charity in the two weeks before Christmas, Cummings added.
In May, all Gurkha veterans with a minimum four years´ service won the right to settle in Britain after a high-profile legal battle led by actress Joanna Lumley.
The Ministry of Defence has since set up a resettlement office in the Nepalese capital Kathmandu to brief applicants about living in Britain -- but Cummings said none of the Gurkhas he had so far seen had been to the center.
"Having not been through any preparation in Nepal prior to arrival, they´re coming here with no resources to back them up and no means of sustaining themselves," he said.
Hugh Milroy, chief executive of Veterans Aid which deals with homeless former service personnel, had already seen a case of a Gurkha who ended up on the streets shortly after arriving in Britain.
"We have already had experience of someone arriving at our charity having been in the country two days and ending up homeless," he told BBC television.
The defence ministry insisted it was doing "a great deal to prepare former Gurkhas and their families for life in the UK."
More than 2,000 people had attended the resettlement centre in Nepal and arrangements were in place in Britain to help bring the ex-soldiers into the welfare system, the ministry said in a statement.
About 200,000 Gurkhas fought for Britain in World War I and World War II and more than 45,000 have died in British uniform. Around 3,500 now serve in the British army.
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