Cancer patient Mandie Stevenson had to postpone a bucket list trip to New York after she accidentally labelled herself a terrorist on her visa waiver form.
The online application asked if she was seeking to or had ever engaged in terrorist activities or genocide.
Mandie, from Falkirk, mistakenly answered "yes".
The 29-year-old, who was diagnosed with terminal breast cancer in 2015, only realised her error when her application was rejected.
It meant she had to postpone a dream break to New York and make an emergency trip to the US embassy in London to persuade officials she was not a security threat.
After a couple of intense interviews, a full visa was granted - but the US authorities could not guarantee it would arrive in time for her flight.
Mandie was advised to rebook her trip, which she was taking with her boyfriend Ross, for a later date.
It cost her more than £800 to rearrange the trip for next month.
Mandie told Mornings with Stephen Jardine she was amazed when her application was rejected.
"At first I thought it was a bad dream and then I realised what I had done," she said.
The Esta (Electronic System for Travel Authorization) is an online form, which UK citizens can use to waive their need for a full US visa.
One of the questions reads: "Do you seek to engage in or have you ever engaged in terrorist activities, espionage, sabotage, or genocide?"
Mandie said she first attempted to fill in the form on her tablet, but it had crashed - so she tried again at work the next day.
She said: "I believe I ticked 'no' and then when I have scrolled down to click confirm, I think it has nudged and moved. That's the story I'm sticking to.
"A lot of people have said 'how on earth could you do that?' but to me I've done it really easily."
Mandie said the mistake was "embarrassing" but she thought it would be easy to correct.
However, the American embassy in London told her it was "the worst box you could have ticked".
Mandie had to go to London and pay £320 for an appointment to get a full visa.
After a couple of interviews her application was accepted, but she was told it would take three to five days to be granted.
Mandie said she told them she would miss her flight but the officials advised her to change her plans.
"I pleaded but they just said 'change your holiday'."
Mandie said she had hoped the embassy or the holiday firm would be sympathetic because she has cancer.
"I live in 12-weekly cycles because I get scanned every 12 weeks," she said.
"I book my holidays in very specific times and this New York trip was going to be before I get another set of scan results, so I was really looking forward to it.
"It was stress that I didn't need.
"I thought because it was a genuine error it would be quite an easy fix but I was quite wrong."
Simon Calder, travel editor of the Independent, said the question on the Esta visa waiver form was "completely pointless".
"Nobody who was engaged in terrorism, espionage or genocide would ever tick 'yes'," he said.
"I don't imagine that anybody has ever deliberately ticked this box.
"But once you are on that list you are never going to get off it."
He said: "America is completely unforgiving. If that box gets ticked for whatever reason, immediately it's as though the alarms go off, the shutters go down and you are into a spiral of despair."
He said the consequence was a stressful interview and the extra cost of applying for a visa rather than a much cheaper Esta.
He said the best advice was not to book a trip until you have all the paperwork in order.
Mandie told BBC Scotland her bucket list also includes a trip to Canada, meeting football star Steven Gerrard and a visit to Thailand.
But first she will get her trip to New York.
"I'm happy again and I'm keen to get going," she said.