Currently, HMRC employs 8,500 staff who answered 48% of calls in 2010/11 and 74% in 2011/12.
The latest decision brings forward HMRC’s 2015 target for answering calls to March next year.
Homer said the decision to move the target nearer was made after a consultation with the Joint Initiative on HMRC Service Delivery, which comprises of several professional bodies and charities.
Homer said: “I am reprioritising our resources to make this additional investment possible, without impacting our other core customer services.
“We remain committed to offering more online services and other ways of serving customers, which will ultimately reduce their need to call us. But in the meantime, this investment will give customers what they deserve: a much more responsive HMRC.”
This is the seventh occasion where HMRC and the JIHSD have worked together since the Treasury Select Committee recommended HMRC work more closely with professional bodies in 2011.
HMRC has been plagued by complaints that resources are overstretched after a series of blunders with pension and tax administration in 2010 and 2011.