When primary school teacher Sian Goodspeed had her daughter in 2008, she attempted to go part-time but found it didn’t give her the flexibility she needed, so she turned to tutoring. She began tutoring at her home, advertising locally and gaining customers through word-of-mouth. Based in Buckinghamshire, a grammar school area, Goodspeed found tuition for the 11-plus (the grammar school entrance exam) was in demand.

A year later, Goodspeed tendered for, and won, a tutoring contract with the Vale of Aylesbury Housing Trust. This involved running 11-plus classes for children who lived in houses it owned, which the trust would pay for. She set up the project, called Tuition Plus, which provides core maths and English skills tuition for 48 children, as well as help with the 11-plus.

“I employed more tutors and took on admin staff, who are crucial in this kind of business to keep everything running smoothly. And I made sure I had a good accountant,” Goodspeed says. As the business, now trading as Flying Start, has grown, she has invested in premises in Chesham, Buckinghamshire. Goodspeed no longer tutors herself, instead focusing on business development. It now has 18 staff, teaches around 350 children in term time and runs holiday courses. Turnover is around £550,000 annually.

With more teachers leaving the profession – a Guardian poll in March found that in England 43% of state school teachers were planning to go in the next five years – the number of private tutors could be set to grow. Four in 10 state school teachers (pdf) have been paid for private tuition at some point in their careers.

And their services are in high demand; in September, a Sutton Trust report found that 42% of state-educated children in London and 25% elsewhere in England and Wales had received private tuition. In 2005, 18% of children in England and Wales had received private tuition.

Meanwhile, if Theresa May goes through with the proposal to lift the ban on new grammar schools, more parents could be looking for exam tuition for children taking the 11-plus.

Susan Hamlyn, director of the Good Schools Guide education consultants, says: “Any increase in academic selection will see lots more business for tutors [...] there has already been an explosion in the number of tutoring companies and there will certainly be lots more [opening] if the ban is lifted.”

Peter Lampl, founder and chairman of the Sutton Trust and chairman of the Education Endowment Foundation, says: “Sutton Trust research has shown how important tutoring is for the 11-plus. Those parents who can afford it give their children a significant advantage over those that can’t.”

Adam Muckle is a private tutor and president of the Tutors’ Association, which launched in 2013. The association has about 150 tuition companies among its members and around 250 individual tutors. He says tutors are also in demand because they give parents greater choice. “People want to focus on their children’s individual needs,” he says. “Good tuition will always compliment the good work being done by school teachers – 50% of the children I tutor, for example, have mild educational special needs. They often need the support as they are not getting the individual attention at school.”

Lorrae Jaderberg, founder and co-director of tutoring and education consultancy JK Educate, is also an ex-teacher who, as well as being a deputy headteacher, was a fully trained special educational needs coordinator. “I could see that there was a need for individual tutoring, for [support for parents in the] transition of children from primary to secondary, and generally just help with educational matters,” she says. So she set up an education consultancy in her name that encompassed these services, which quickly developed.

“I was well-known in my field and in my area, Barnet, north London, and people just gravitated towards me. The phone never stopped ringing. After four years, I realised I needed help so I brought in a colleague, Katie Krais, to help me, and we founded JK Educate.”

Six years on, the business is growing on average 20 to 30% year on year, and now serves the whole of London.

Jaderberg describes it as a concierge service for education. “We assess the children for potential and for achievement. We work out which schools they need to go to and tutor them, the whole thing from start to finish.” JK Educate also runs tutoring sessions via Skype for overseas clients in South Africa, the US and Saudi Arabia whose children are joining the UK education system. Its tutors are ex-teachers, retired teachers and teaching graduates, all are trained at the JK Educate Academy.

While face-to-face sessions still account for most tutoring business, online tutoring is a growing area, says Muckle, and it’s attracting interest from entrepreneurs and investors.

James Grant started his online tutoring business TutorTap when he was still working in the chief of staff’s office at Barclays. TutorTap is a website that connects pupils that need extra support with students at top universities who want to earn extra money through tutoring.

This year, the TutorTap team became part of MyTutor, an online tutoring service for out-of-school tuition, which has delivered more than 50,000 online lessons since it launched in 2012. It has around 1,200 tutors, mostly university undergraduates and postgraduates from top universities, on its books. They teach 6,000 pupils in the UK and abroad in more than 60 subjects. Grant now has co-founder status at My Tutor and runs its school-facing operation. “I think this is a rapidly growing and really exciting area,” he says. “The tech has caught up, and the parents are becoming far more tech-enabled.”

Milo Rignell, Mathias Pastor and Neil Saada, all still in their second year at university, have secured €300,000 (£267,000) from three investors for their startup Teech. Teech is an app that connects pupils with university students at top universities who can give them instant help.

Rignell explains: “You can type your question, add a little photo and send it off to all the subject approved tutors. All our tutors will receive the notification and whoever is available will then call the pupil and give them a session.” The app went live in October 2016 and has had around 1,500 downloads so far. Most of these are subscriptions, which cost £100 per month.

Challenges come alongside the opportunities of the tutoring business. No regulation system exists for private tutors, so, effectively, anyone can set up. “We see a lot of very sub-standard tutoring carried out by both companies and individuals who should not be doing it,” says Jaderberg.

So while it might seem that tutoring is an easy win, you have to be trained and effective to survive – parents expect results and drop tutors that don’t deliver them. “It’s very easy to access the market but it’s also very easy to exit,” Muckle says. “[Of the many] tuition companies out there, it becomes very clear over time which are successful and which ones aren’t. Who survives and who doesn’t is a mark of how much they care about education, as well as running a business.”

• This article was amended on 27 October 2016. An earlier version said that Teech secured €100,000 (£90,000) from three investors and that the app launched in September 2016.

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