A total of 29 per cent turn to their parents for financial help while away, the poll by Post Office Travel Insurance found.
As many as 20 per cent run out of money in the first three months, with the amount that parents give their children averaging £772.
Gap year travellers also help fund their trips with credit cards, overdrafts, bank loans and student loans.
Based on responses from 1,024 people who had been on gap year trips in the last five years, the poll also showed that nine per cent resorted to finding work while away to help finance their trips.
As many as 43 per cent of those who got jobs abroad did not have a working visa despite this being a legal requirement.
The survey also showed that the average spent on a gap year trip, including flights and spending money, was £3,736;
Post Office Travel Insurance head Rachel Croft said: “These findings show that people don’t always take adequate steps when preparing for such a big trip away and as a result often end up in financial trouble.”