In the fashion business, faux pas can be costly. In order to hem back the risk, some retailers are increasingly turning to trend forecasting.

For an average annual fee of $7,000 to $15,000, customers get access to forward forecasts of fashion trends and data offering ideas for colors, fabrics and cuts, often broken into categories like 'industrial' and 'aquatic'.

The forecasting companies offer analysis of fashion shows, data on the current market offerings and -- for an added fee -- bespoke research and consultancy services. The data are generated by teams of staff employed to trawl art exhibitions, events, restaurants and even scientific journals.

Fashion companies use the data to plan their latest collection or catwalk show, with the online services replacing the bulky and intermittent style books that designers and merchandisers used to receive.

'We have seen double digit growth over the last two years and in 2013 we are seeing the highest increase in customer growth for three years,' says Julie Harris, chief executive of Worth Global Style Network, a U.K.-based forecaster that counts every Fortune 500 apparel brand among its 3,600 corporate subscribers.

WGSN, which is part of the Top Right Group, in July bought the online division of Mudpie, a smaller rival that operates mainly in the children's market, for an undisclosed sum. The physical stylebook service that WGSN didn't snap up has now been liquidated.

The company will also launch a retail analytics tool in the next month targeted specifically at comparison shopping, a service companies use to check up on the competition and gauge demand for similar products.

'[Fashion forecasters] have always been used but they're more accessible now because of the technology,' says Marks & Spencer creativedirector Belinda Earl, who has just launched her first collection for the U.K. high street bellwether. 'They are important, not always to lead but to re-evaluate and help confirm you're on the right track.'

'We use [trend forecasters] to support, validate and give us confidence we're on the same page,' said Anna Clarke, head of womenswear for J Sainsbury's Tu clothing range.

'We can't get rid of risk but we can mitigate risk,' says Frank Bober, founder and CEO of U.S.-based fashion trend forecaster Stylesight.

Mr. Bober's Stylesight has 3,000 different corporate subscribers, representing 40% growth over the past four years.

Forecasters claim to save their clients travel expenses, the cost of freelancers who might be paid to photograph trendy people, and time spent trawling the vast cache of fashion data that are already available on the Internet. Then there is the benefit of being on-trend, which can translate into increased sales.

'They [forecasters] take the information and package it in a way that speaks the language of the retailers and manufacturers. Then it's our job to decide what makes sense for our business; we have to filter it again,' says Sofia Wacksman, vice president of trend for Kohl's Corporation.

She said that while the company relies heavily on forecasters, it also follows blogs and fashion websites, takes several annualoverseas trips to leading fashion cities, follows the catwalk shows and trawls vintage trends.

Retailers are also turning to number crunchers to improve execution. U.K. start-up EDITD trawls the Internet to gather data on who's selling what, how many products are flying off the virtual shelves and how much are they going for to guide companies in their merchandising decisions.

Founders Julia Fowler, a designer, and IT developer Geoff Watts believe retailers need real-time data to decide when to put something into their storefront, when to discount it and when to take it away to make space for new items.

With 20 staff and a handful of clients, the company expects to be twice as big this time next year.

EDITD's database of images and information churns out frequent reports and reference tools including a comparison-shopping tool and a social monitorfunction which looks at what people are commenting about online.

New entrants are joining the market. ITC Limited, an Indian cigarettes-to-hotels conglomerate, later this year will launch a fashion analytics system that mines a company's own historical data to 'analyze past designs and bring out the aspects that have been popular and feed this information back into the design process,' the company said last month. It has yet to confirm the cost of the service.

Many retailers say the information forecasters provide has become an important part of how they tap consumers, who spend less, shop online more and demand the latest outfits in increasingly tight time frames.

'Fashion moves so quickly,' Kohl's Sofia Wacksman said. '[Companies] like Stylesight or WGSN, which are updated every day, are really useful in order to make sure we have the right information. They offer us an industry eye on all of the information, broken down by print, color and classification like sweaters of woven tops.'