Last week she told MPs that she had accurately declared all conflicts of interest, and that she had also  helped to write the Bank's code of conduct.
However, she failed to declare that her brother worked at Barclays, one of the banks she will be overseeing.
Ms Hogg apologised but one MP called for her to resign.
Ms Hogg, who has worked at the Bank since 2013, did not declare her brother's role, which is in Barclays' strategy office, until she submitted documentation to MPs, who last week reviewed her appointment as deputy governor for banking.
The oversight has an extra poignancy since Ms Hogg helped to produce the Bank's code of conduct.
Treasury committee member, John Mann, said: "It is simply incredible that such a senior person at the Bank of England has behaved in this manner.
"Last week Charlotte Hogg proudly told this committee that she actually wrote the Bank's code of conduct which she has now admitted to repeatedly breaking."
Ms Hogg said in a letter, sent last week, but only revealed on Tuesday: "I should have formally declared my brother's role when I first joined the Bank. I did not do so and I take full responsibility for this oversight."
She said she would ask the Bank's Monetary Policy Committee, Financial Policy Committee and Prudential Regulation Committee, on which she now sits, to review if further steps were needed to manage the potential conflict of interest.
Employees of the Bank of England must declare personal relationships, sign up to a code of practice, and step back from decisions where there is a conflict.
Charlotte Hogg, the Bank of England's newly appointed deputy governor for markets and banking, has admitted breaching the Bank's guidelines.