Bemilo says its system, to run on the British Vodafone network, will allow parents to stop their children from going online, texting or making or receiving calls during certain hours.
"It's a SIM that is just like any other SIM you would buy for any other network, but it enables parents to have full control in the context of safety," Simon Goff, founder and chairman of Bemilo, told the BBC.
"They can allow or disallow certain contacts to call them, and they can set the times of day the phone can operate."
The SIM would help protect children from mobile phone bullying or "sexting" through unwanted phone calls or texts, Britain's Family and Parenting Institute said.
The system will enable parents to help ensure their children's safety, Goff said.
For example, he said, if parents wanted to deactivate the phone during school hours, they could do so remotely from a Web site on their computer.
However, even if the child's phone is disabled, parents can manage the handset in such a way that they are able to reach the child and the child is able to contact them, he said.
Bemilo said in a survey of 2,000 parents, 25 percent reported their children have been subjected to cellphone bullying.
Swim Week Miami Beach 2014 [PHOTOS]