"These failings took too long to be identified and then far too long to be fixed."
An investigation found that Santander did not transfer funds totalling over £183m to beneficiaries when it should have done, affecting 40,428 customers.
These weaknesses meant the probate and bereavement process would start but it would stall and remain incomplete, meaning that funds would not be transferred to those who were entitled to them.
The FCA says Santander also failed to disclose information relating to the issues with the probate and bereavement process to the regulator after it became aware of them.
Since 2015, Santander has carried out remediation exercises to transfer funds from affected accounts to beneficiaries.
Where appropriate, Santander has also paid interest on the funds to beneficiaries to compensate them for the delay.
Santander did not contest the FCA’s findings and agreed to resolve the case and therefore qualified for a 30% discount. Were it not for this discount, the FCA would have imposed a financial penalty of £46,882,500.
Mark Steward, executive director of enforcement and market oversight at the FCA, said: "These failings took too long to be identified and then far too long to be fixed. To the firm’s credit, once these problems were notified to the board and senior management, they were fixed properly and promptly.
"But recognition of the problem took too long. Firms must be able to identify and respond to problems more quickly especially when they are causing harm to customers. The FCA will continue to be on the lookout for firms with poor systems and controls and will take action to deter such failings to ensure customers are properly protected.'
