Serko slipped to a $866,000 loss for the six months to September 30 from a $920,000 profit for the year-ago period.
A 46 per cent surge in operating expenses helped overwhelm a 29 per cent increase in revenue to $15.2 million for the half - in line with guidance of an increase of 20 to 40 per cent for the full year.
• US giant Booking.com buys into NZ's Serko
Ebitdaf fell to $1.4m from the year-ago $1.5m.
The debt-free company's cash reduced from the $19m last year to $10.3m. Cash was replenished by a $45m raise during October, but this morning the company said cash burn would accelerate in the second-half as it pushed into the US.
Serko said more than 1300 corporate customers used its Zeno booking and travel expense platform in the first half as net total customers increased by 327.
Travel platform revenue rose to $9.2m from $7.7m in the prior comparable half-year. While bookings out of Serko's home markets in New Zealand and Australia were softer, reflecting weaker economic conditions, that was offset by a combination of revenue growth in other markets and more bookings on the firm's new, higher-margin Zeno platform.
Its all-important metric of annual transactional monthly revenue which the company uses as a proxy for its growth outlook, reached a peak of $26.2m during the period, up 35 percent from $19.4m in the same period a year earlier. Total recurring revenue rose 38 per cent to $13.3m from $9.6m in the previous half-year.
The ultimate impact of higher costs, which included research and development expenses rising by $5.1 million to $8.9 million, saw half-year cashflow turn negative at $474,000, compared with positive cashflow of $14.3m in the first half of the previous year.
The numbers were in line with preliminary results released on October 24.
Serko shares surged during October (see below) after the company sold $40m in new shares at $4.04 a piece, with US travel giant Booking.com taking a 4.7 per cent stake for $17.5m as part of the action.
Staff including co-founder and chief executive Darrin Grafton and chairman Simon Botherway sold $16m shares as part of the transaction.
Grafton told the Herald that Booking.com would promote Serko's Zeno platform.
He expected Booking.com would be able to offer some smarts about what it had learned in the hotel market, and from other sites in its stable such as RentalCars.com and OpenDining.com.
"When the largest company in the world in your sector backs you, it's pretty good," he said.
Serko shares closed yesterday at $4.58 for a $415m market cap.
The stock is up 52.67 per cent for the year.
On October 25, shares jumped 29 per cent from $3.42 to $4.40 as trading resumed after a halt before the Booking.com buy-in was revealed.
Serko listed in 2014 with shares prices at $1.10.