M&S is expected to face disruption from a cyber attack until July, impacting contactless payments and Click and Collect services.
Customer data was stolen in the attack, but no passwords or card details were accessed.
M&S operating profits to be reduced by £300 million due to the cyber attack, with experts mentioning that attacks on iconic institutions are often not sophisticated.
The cyber attack has been linked to a group called Scattered Spider using ransomware; other retailers like Co-op, Harrods, and the Ministry of Justice’s Legal Aid Agency have also been targeted.