The Wakefield-based discount retailer said improvements in quality and range of products and market share gains helped increase like-for-like sales by 2.7 per cent.
Underlying earnings rose 7.7 per cent to £32.5m on revenues of £161.4m in the six months ending July 2015.
The company said the special dividend of 15p reflects the “ongoing strong cash generative nature of the business”.
Richard Hayes, chief executive, said: “It is encouraging to report another strong set of interim results with growth in both revenue and profit.
“We continue to deliver on each of our four growth pillars: growing like-for-like sales, rolling out new stores, delivering business efficiencies and growing our online businesses.
“It is also pleasing to announce a special dividend, in keeping with our commitment to return surplus cash to shareholders.
“We continue to focus resolutely on maintaining our very strong competitive position and further improving and developing our value retail proposition.
“The business is well prepared for the important Christmas trading season, and we remain confident of the Group’s future prospects both in the near and longer-term.”
In an interview with The Yorkshire Post, Mr Hayes said the company is currently reviewing the likely impact of the National Living Wage, which comes into effect next April.
The group employs 8,000 people and spent £27.5m on wages in the first half of the year.
Mr Hayes said: “We have to look at our five-year plan and make sure we can mitigate the cost of it and make the action that we think is relevant while maintaining the value retail proposition that we have.”
Asked if this meant redundancies, he said: “We won’t rule anything in or anything out, but I would be disappointed if it resulted in that. I think there are other oppportunities for us to explore.
“This won’t affect our strategy in terms to our ongoing roll-out which continues to generate in the region of 500 new jobs each year.”
Card Factory opened 36 new stores in the period, bringing total estate to 800. It plans to open a total of 50 this year.
The company was founded by Dean and Janet Hoyle in 1997.