Third-ranked cabinet minister Gerry Brownlee will represent New Zealand at Margaret Thatcher's funeral next week.
The decision to send Mr Brownlee to London for the service at St Paul's Cathedral on Wednesday was confirmed to NZ Newswire by Prime Minister John Key's office.
Lady Thatcher, Britain's first woman prime minister, held office from 1979 to 1990.
She died on Monday aged 87.
The British government invited about 200 countries to send official representatives.
Wednesday's service will begin at 11am after Lady Thatcher's body is transported from Westminster with full military honours.
St Paul's Cathedral will be packed with 2300 guests. The Queen will attend the funeral of a former British leader for the first time since Winston Churchill died in 1965.
Australian Prime Minister Julia Gillard is expected to announce her country's representative on Friday.