The business maxim to "Keep It Simple, Stupid" is not just common sense, it could also make your business money, according to a new index.

The Global Brand Simplicity Index polled more than 6,000 consumers and asked them to chart the ease of which they understand what’s being offered to them by leading brands.

Interestingly, a number of premium brands performed well in the survey, suggesting consumers are more likely to spend with shops which invest in excellent customer services and offer easy-to-understand explanations about their offers, even if they cost more than their rivals.

John Lewis, Virgin Atlantic, Waitrose, Marks & Spencer and Hilton hotels all ranked in the top 20 of 125 brands for simplicity and ease of understanding.

Brand experts Siegel+Gale, which collated the index, believe up to 38% of consumers are willing to pay more for simpler experiences.

"Ultimately, the more complex a brand’s relationship is with its consumers, the more difficult it is to cultivate consumer trust," Liana Dinghile, group strategy director at Siegel+Gale told Huffington Post UK.

"Clear, credible, and consistent communications will send the correct message, but to achieve success, brands must ensure that they apply simplicity to target areas that really add value and can make a difference to their customers' worlds.

"The Global Brand Simplicity Index clearly demonstrates that if you simplify your business you'll reap the benefits."

By sector, high street banks ranked a lowly 22nd out of 25 industries for simplicity, but by offering simpler services, Siegel+Gale believe they could charge up to 3% more for their products. That's equivalent to the entire industry making £859m more.

Individually, Barclays ranked 120th out of 125 brands, no doubt hampered by the recent London interbank lending rate and payment protection insurance scandals. The Royal Bank of Scotland ranked just behind in 111th.

Some banks performed noticeably better however; First Direct ranked 12th out of the 125 brands listed, helped by its successful implementation of the online dialogue service, online banking tools and "excellent" customer service.

Another sector which was labelled as overly complicated was the energy sector: In light of Ofgem’s calls for simplified bills and energy tariffs earlier in October 2012, not one of the major providers ranked higher than 108th in the survey of 125 companies.

The worst-ranked energy provider was EDF Energy at 122nd, which failed to make an impact despite its large marketing push around the Olympics. Its billing was cited as “still complex” and “not easy to understand” by consumers.

Edging in slightly ahead was nPower, ranked 121st, followed by Scottish Power (110th), Scottish & Southern Energy (109th), British Gas (108th) and EOn (115th).

By making their tariffs easier to understand however, Siegel+Gale estimate they could generate an extra £892m in a "simplicity premium", as consumers would be prepared to pay 3% more for better simpler experiences.

Other top brands praised for their ease of understanding were Google, McDonalds, Lovefilm, Asda and Sainsbury's, while the most complicated brands frustrating consumers were Ryanair, Axa PPP (healthcare) and Talk Talk.