Pupils at Fortismere School in Muswell Hill were left unable to access their exam results this morning after a website glitch.
Parents at the school said the disruption caused stress and upset to their children.
It is understood the school was working throughout the morning to fix the IT portal where results were to be displayed, and students were eventually able to access their results online at about 11.30am.
Jenny Papaeliopoulos, whose daughter was receiving her results today, said: "It's been frankly completely farcical. They have messed up posting the A Level results."
Jenny said her child was "in floods of tears – and so has half of the school year", continuing: "It's not like they didn't know this date was coming, it's set in stone."
Jenny, who works in the NHS, said her child had luckily met their university offer, but had been forced to call school staff in order to find out her actual grades.
Another parent said: "The school sent a note after more than an hour to say there was a glitch."
She said she similarly had to "wrestle" her child's results from a teacher over the phone.
In an email, co-headteachers Zoe Judge and Jo Davey and director of sixth form Madeleine St Amour wrote to parents: "Please can you let your son/ daughter know that we have posted a message on google classroom regarding the delay in exam results this morning.
"We are working with Cloud School to resolve the issues as quickly as possible. If your son/daughter has a concern regarding their UCAS offer they can call the school or come in and meet with one of the Sixth Form team.
"We apologise for the undoubted stress that this has caused this morning."
It is understood A Level results were viewable on the online platform at around 11.30am.
Fortismere School's co-head Jo Davey told this newspaper the school at responded to the computer issues by inviting pupils in for an "old-school physical collection" of their results, and phoning students where possible.
Speaking about the results in general, Ms Davey and Ms Judge said: "Our students have impressed us throughout the last two years of interrupted education. Their resilience, determination and hard work, supported by their teachers, have enabled them to overcome many of the difficulties Covid has presented."
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