The Self Assessment Online portal has been restored to service in the mid-afternoon on Thursday after breaking down on the busiest day of the tax year.
An HMRC spokesman confirmed that the Self Assessment online filing service experienced 'technical difficulties' on Thursday morning, which meant that some taxpayers could not file online.
Just after 3.30pm, the department advised: "The system is now rapidly returning to normal levels of service." Because of the disruption, it also promised that no-one who files electronically or by paper by midnight Friday 1 February will face a penalty.
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