Boohoo’s pre-tax profits leapt 129% to £14.4m during the six months ended 31 August, while sales increased 40% to £127.3m on the previous year.
Gross margin fell by 480 basis points to 55.3% due to “planned investments in price and promotions”.
The etailer, which has just expanded into kidswear, credited a broader product range for driving growth. Active customers increased 28% on last year to 4.5m people.
Joint chief executives Mahmud Kamani and Carole Kane said they expect full-year revenue growth to be between 30% and 35%, reflecting tougher second half comparatives.
“Following the success in the first half of the year we will continue to look for opportunities to invest in marketing campaigns and our customer proposition to drive future sales growth and improve customer lifetime value,” they said.
“We will also be making significant investments in our IT systems and ecommerce platforms. Consequently EBITDA margin for the full year is expected to be around 11%.”