The prior year was hit by flooding in Auckland and Cyclone Gabrielle.
As at Monday, Tower had closed 97 per cent of Auckland Anniversary and Cyclone Gabrielle FY23 claims, it said.
The first half business-as-usual claims ratio was 49.7 per cent versus 51.1 per cent a year earlier.
Customer numbers declined 1 per cent to 309,000 vs 312,000 in HY23, partly due to tightened risk appetite for high-theft motor vehicle models.
Tower said it would pay an interim dividend of 3 cents per share.
The shares closed on Monday at $0.795.
It expects full-year underlying net profit to be greater than $35m, which assumes full use of the large-events allowance.
Tower has set an allowance of $45m for FY24, which remains unused.
Any unused portion of the allowance at year-end will increase underlying net profit after tax (NPat) and consequently improve the full-year result.
The first-half gross written premium (GWP) was $291m, up 20 per cent on the year.
It said this was predominantly driven by prior period rating increases designed to mitigate the impacts of inflation, crime, and increased reinsurance costs after the 2023 catastrophes.
The management expense ratio (MER) improved to 31.3 per cent versus 35 per cent in the prior period.
“Tower is continuing to drive business efficiencies from investments in digitisation and streamlining the business. Tower’s Suva hub is now answering half of all New Zealand customer sales and service calls,” it said.
It expects full-year GWP growth to be between 10 per cent and 15 per cent and MER to be between 30 per cent and 32 per cent.