Shrewsbury Crown Court heard how on May 13, Kieren Baxter, 18, attacked Singh Bajwa in Ketley Bank, Telford, leaving him with cuts to his neck and needing 10 stitches to his hand after the knife got stuck in his hand while trying to defend himself.
Phillip Beardwell, prosecuting, said Baxter, who was 17-years-old at the time of the attack, and co-defendant Chloe Watts, 18, had called for a taxi to pick them up from the new Asda in Malingsgate at about 10pm.
Mr Bajwa, who was working for Central Taxis, answered the call and picked up Watts and Baxter to take them to their destination address in Ketley, where it turns out neither defendant lived.
The journey passed without incident, but when they reached the destination in Mossey Green, a secluded cul-de-sac, Baxter grabbed Mr Bajwa around the neck and pulled him into the seat.
He then took out then took out the knife and attacked Mr Bajwa with it.
Mr Beardwell said: "He began to cut his neck. Fortunately they were not serious wounds.
"Mr Bajwa then reached for the knife to protect himself and it became lodged in his hand and broke, which required 10 stitches in hospital.
"The pair then fled the taxi and he called the police and was left distressed and shocked."
The following day both Baxter and Watts were arrested where they lived at the time on Dodmore Grange, Randlay, and in police interview both initially lied to police.
Watts said they did not get a taxi and Baxter said there was no violence and referred to himself as a "pacifist".
Eventually both admitted to police they had been smoking cannabis and admitted to the offences and Baxter told police he had dumped a green hoodie he was wearing and the rest of the knife.
Watts admitted she had told Baxter to do so to avoid detection.
The court heard how Baxter had been kicked out of his house in Hove, near Brighton, by his family because of his uncontrollable cannabis addiction and had ended up in council housing in Telford.
Dan White, defending Baxter, said: "There are two sides to this young man. One when he is on drugs and one when he is law abiding, diligent, polite and hard working.
"He is remorseful and apologises for his behaviour which he accepts was appalling."
Debra White, defending Watts, said she was a vulnerable young woman who has learned her lessons.
Judge Robin Onions said: "The carrying of knives is not acceptable.
"You put it against his throat from behind – he must have been terrified.
"There you made at least four linear cuts, they were not deep and the injuries are superficial, but he must have been terrified.
"You both then fled without any care for him or whether he would need medical assistance."
Baxter had previously pleaded guilty to unlawful wounding and possessing the knife.
He was sentenced to 16 months in a young offenders institute.
Watts, now of Sutton Hill, Telford, had pleaded guilty to assisting an offender and possessing a knife.
She was sentenced to six months in a young offenders institute suspended for two years.
She was also ordered to carry out 150 hours unpaid work.