A journalist uses his mobile phone to take a picture of the 5G logo prior to the auction of spectrum for 5G services at the Bundesnetzagentur headquarters in Mainz, Germany, March 19, 2019.

Superfast 5G internet could add £15.7 billion ($20.7 billion) to the U.K. economy every year by 2025, according to Barclays.

However, the opportunity could be missed as the majority of business leaders still don't know what 5G is, according to a research note published by Barclays Group.

According to the report published by the lender's corporate banking arm on Wednesday, an "optimistic scenario" – an accelerated 5G rollout and quick uptake by businesses and consumers – would see a £15.7 billion increase in annual business revenue by 2025.

At the current rate of development, U.K. businesses would see revenue increase by £13 billion per year, while a slower-than-anticipated rollout would add £8.3 billion to business income, Barclays predicted.

Despite the technology's potential impact on profits, Barclays found that almost 40 percent of business leaders still weren't sure what 5G is. Just 15 percent of businesses had thought about how to harness 5G, the report showed, noting it was clear that a majority of businesses "are not ready to successfully join the 5G revolution."

However, the note emphasized that the optimistic scenario could become a reality for the U.K., where the government has pledged to invest £1 billion in digital infrastructure and incorporated 5G plans into its industrial strategy. Barclays also noted that telecoms firms are already testing the technology across Britain. Vodafone will launch 5G trials in 19 U.K. cities by the end of 2019, while competitor EE will turn 5G on in six British cities this year.