The mentors come from the small business community and can be accessed through mentorsme.co.uk, the national mentoring portal owned and operated by the British Bankers' Association (BBA).
The 15,000 trained recruits joined 12,000 existing business mentors from across 115 mentoring organisations available through the portal.
The volunteer mentors have been recruited and trained over the past 16 months as part of the £1.9 million Government-funded Get Mentoring project, delivered by the Small Firms Enterprise Development Initiative (SFEDI).
Their aim is to harness the experience of business people to train them as mentors and share their expertise with new and growing businesses increasing their success rate.
Business minister Michael Fallon said:? "Small businesses are vital to our economy and we are determined to help them get on and succeed.
"We have invested in mentoring because we know that good mentors can provide the practical advice and support that an entrepreneur needs to take their business idea to the next level.
"They have been there and done it and can pass that experience on. I want to encourage people to come forward and take advantage of the mentoring network."
Ruth Lowbridge, executive chair of SFEDI, said: "We are thrilled to have brought the mentor training and resources to so many volunteer mentors and are extremely grateful to our network of strategic and delivery partners who have provided tremendous help through engagement with their members and their business and personal networks."
