A snap-happy British teen posted pictures of her New York City dream vacation on Facebook — and got socked with a nearly $6,000 phone bill, her mom says.

Casey Snook, 14, failed to block her data-roaming on her iPhone when she hit the Big Apple for a five-day trip with her mom, Kate, and her mom’s fiancé.

As Casey gleefully posted dozens of shots from her visits to Times Square, the Empire State Building, Central Park and Grand Central Station for her pals back home, the meter was running on her Internet access.

She wasn’t aware of the massive bill until the UK phone company Orange hit Casey’s father’s account for the cash.

“This is about the extortion of a 14-year-old girl,” Kate Snook told the UK’s South West News Service.

“When I heard about it I felt physically sick. Casey was very upset and embarrassed and I was in tears.”

“She was only using it for the normal teenage stuff, updating her friends with what she was up to and this and that,” Kate Snook said.

“It was an experience. She was just using Facebook like a normal teenager to tell her friends.”

Casey’s dad, Victor, who is divorced from Kate, pays the bill, and the account is in his name.

The company says it sent Casey a warning text when she hit $500 in charges. It claims she clicked “yes” when asked if she wanted to continue.

Her parents have set up a payment plan to pay off the bill but are still demanding an explanation for why the phone company didn’t send further warnings or try to contact Victor, the account holder.

“I can’t believe that a company would let a bill which is usually [$75] get up to that level,” said Kate.