Other reasons for travelling apart were work or other commitments, and different leave patterns.
Another reason was a failure to agree on a choice of a destination.
Meanwhile, 4% of those who travelled without their partner said it was cheaper to go alone, while 3% left a partner behind to look after the children or pets.
LV= travel insurance managing director Selwyn Fernandes said: "The way we travel has fundamentally changed in recent years with people going away more frequently and taking part in a wider range of activities."
The expert went on to say: "People no longer have to spend all of their holidays with their partner or compromise on where they both go on holiday."
Of the solo trips, 52% were made by women and 48% were made by men.
The research showed that women opted for city breaks with friends, spas and short-haul beach trips.
Men, however, seemed to prefer activity-based trips such as golfing holidays and fishing expeditions.