HomeServe's adjusted pre-tax profits rose to £28.7m in the six months to the end of September - 9% up on last time - following record partner signings in the US.
Revenues were up 20% at £314.3m and statutory pre-tax profits rose by 4% to £22.2m.
Chief executive Richard Harpin said: "During the first half of this year we delivered the most rapid period of expansion in the US in HomeServe's history. We added a record number of new US partners, increasing partner households to 49m and making excellent progress towards our long-term target of 80m. Customer numbers in the US increased by 32% and the US now accounts for more than a third of HomeServe's customers.
"We have had a strong start to the year delivering profit growth combined with very good and increasing levels of customer service in all of our businesses. HomeServe now markets to 100m households across five countries with 7.5m customers. The winning combination of customer focus, innovation and a great business model gives me confidence about our future prospects and we remain confident of achieving good growth for the full year in line with our expectations."