A mum was left distressed after a benefits office recorded her as deceased.
Rebecca Marshall, 39, had to prove she was alive to her bank, Braintree Council and Greenfields Community Housing, after the mistake by the tax credits office.
Ms Marshall, of Braintree, has received no explanation or apology and even reported the matter to police, fearing she had been a victim of fraudsters.
A spokesman for HM Revenue and Customs said: "I am sorry but HMRC cannot comment on individual cases due to confidentiality.
“However, we are looking into the matter and apologise for any inconvenience caused to your reader."