Both departing and arriving services were impacted and according to data analytics firm Cirium, the carrier cancelled 43 flights as of 5pm Thursday (25 May) – equating to 5% of all services to and from the London hub.
A spokesperson for BA said affected customers were contacted and offered options, including a refund or rebooking to an alternative flight with BA or another carrier.
"While the majority of our flights have continued to operate, we had to cancel a number of Heathrow flights due to a technical issue," they said. "We are extremely sorry to our customers for the inconvenience caused."
In a statement, Heathrow advised passengers to contact either BA or their travel provider. "British Airways has suffered a technical issue which is impacting some British Airways departing and arriving flights," the airport added.
Last December, a technical problem grounded a number of BA flights due to depart the US, which caused knock-on effects with crews and aircraft in the wrong place to resume schedules.
Prior to that, in February 2022, BA passengers faced chaos at Heathrow after the airline cancelled all short-haul flights from the airport due to a technical glitch – which was followed by another tech meltdown in March 2022.
Rory Boland, editor of Which? Travel, said: "As we approach the busiest travel period since before the pandemic, it’s not a good look for British Airways to once again be cancelling flights because of an IT meltdown, especially after the significant disruption it caused travellers last year.
"If your flight with BA is cancelled this half term due to these ongoing technical issues, you will be entitled to a refund or rebooking at the earliest available opportunity, including with other carriers if necessary. Passengers are often given the runaround on this right, but it is the law, so it’s worth being insistent."
