The 46-year-old’s offences took place from 2006 until 2009 and related to one victim, and were reported to officers in October last year, at which point he was arrested.
Investigating officer Police Constable Tamzin Ede said: “Simon Thornton displayed predatory behaviour to abuse a child for a prolonged period. He clearly believed he would get away with this offending given how long it carried on and has now rightly been jailed for his abhorrent crimes.
“Simon Thornton’s crimes have impacted the victim through her childhood and into adult life, the offending against her have caused low confidence, depression and difficulties in building new trusted relationships. The victim in this case has shown real courage in reporting and supporting the police investigation.
“This case is one of many that we investigate in the Sexual Offences Investigation Team where we have highly trained and specialist officers who everyday support victims of sexual offences and investigate offences.
“I hope that today’s sentencing encourages victims of sexual offences, whether recent or in the past to come forward and report offences.”
Thornton pleaded guilty to 13 charges of sexual activity with a child over 13, as well as nine charges of taking indecent images.
If you have been the victim of a sexual offence or know someone who has please report it to Surrey Police immediately via 101 (or 999 if it is an emergency).
Support and advice is also available from the National Society for the Prevention of Cruelty to Children (NSPCC) via www.nspcc.org.uk or their helpline on 0808 800 5000.
If you are concerned about your own online behaviour, or that of someone you know, make contact with the Lucy Faithfull Foundation’s “Stop It Now” anonymous helpline on 0808 1000 900 before your activity becomes a problem.