BA claims to have resolved the check-in system IT problems that caused around 100 flight cancellations

British Airways has resolved the IT issues that have kept its check-in systems down all day

British Airways claims to have resolved the IT issues that have kept its check-in system offline all day.

The glitches in the company's check-in systems forced the company to revert to manual procedures, and caused the cancellation of almost 100 flights. Many more flights were delayed.

It is the fourth year in a row that BA flights have been disrupted by IT problems.

The company claimed to have solved the problems in a 4.15pm update on its flight status pages.

"Our teams have been working tirelessly to get the vast majority of customers on their way, with most of our flights departing," it said on the latest updates.

It continued: "Our flights are returning to normal, however there may be some knock-on operational disruption as a result of the issue earlier today.

Passengers travelling from Heathrow, Gatwick, Manchester and London City encountered problems with the company's check-in systems from first thing this morning, leaving them unable to check-in, either online or at the airport.

In response, BA cancelled around 100 flights, almost all of them short-haul, in a bid to minimise disruption with long-haul services. Passengers were invited to rebook for another day or offered refunds.

The official line from BA, posted on its homepage, said for much of the day: "We are experiencing some systems problems this morning which are affecting check-in and flight departures Please check manage my booking for the latest flight information and allow extra time at the airport."

BA staff were forced to checkin passengers manually, which worked but took significantly longer. There also seemed to be some confusion over whether the problem was global, or just affected flights out of the UK.

The IT meltdown is just the latest in a series of IT-related disasters to hit the airline in recent years, which critics claim has been caused by years of under-investment.

It is also facing a record-breaking £183 million fine from the Information Commissioner's Office (ICO) over a Magecart security breach last year.

The airline was also forced to apologise for delays and cancellations in July last year following an IT glitch. And in May 2017, the company had to defend itself against claims that cost-cutting was behind an IT outage that caused a ‘weekend of chaos' - an outage that caused an estimated £80 million in losses.

We will update this story as new information comes in.