Today's fact sheet provides more detail.
MPs can use the value of one business class return airfare to enable their partners to accompany them - they can downgrade their airfares and use the savings to help pay for their partner.
Any additional cost associated with members' spouses or partners accompanying them must be met by members, said Mary Harris, Clerk of the House of Representatives.
"In this respect, there is no additional cost associated with members' spouses or partners accompanying them than if the member had travelled alone.
"All other costs associated with spouses or partners...including accommodation, meals, transport and incidental expenses is met by members."
Costs for Mr Carter's spouse - including a return business class airfare - are covered by the Office of the Clerk, "because of their ceremonial and representational role".
The budget for the tour was $138,000, of which $97,000 was for flights.
"The role of spouses and partners participating in such visits is ceremonial and representative, and an accepted aspect on inter-parliamentary exchanges," Ms Harris said.
"There is an expectation that the spouses and partners of the New Zealand Parliament's delegation will mingle and engage with their counterparts. Establishing these relationships further enhances 'soft diplomacy'".
This year's delegation will visit France, Ireland, Northern Ireland, Poland and Germany over 14 days.
Accompanying Speaker David Carter are National's Deputy Speaker, Chester Borrows, first-term Labour MP Adrian Rurawhe, Green Party foreign affairs spokesman Kennedy Graham, first-term New Zealand First MP Fletcher Tabuteau, and two parliamentary staff.
All the MPs except Mr Rurawhe are bringing their partners.
Mr Carter will lead the trip and said the visit was an opportunity to meet political leaders and strengthen some of New Zealand's "oldest and most significant contemporary relationships with European countries".
The delegation would also mark historic commemorations, including the 98th anniversary of the Battle of Arras in France and the 70th anniversary of the liberation of the Auschwitz Nazi concentration camp.
Some of the tour costs would be met by the parliaments of Poland and Germany, which had invited the Speaker to attend events in their countries.
The estimated budget was less than in previous years. The 2012 Speaker's Delegation to Britain, Croatia and Belgium cost $158,000.
The official itinerary showed the MPs are to begin their tour in Arras, where they will visit a memorial for 41 New Zealand soldiers killed while constructing tunnel networks for the Allies.
They will then meet trade officials, economists and the French parliamentary Speaker, and visit the OECD headquarters and chateau in Paris.
Later, they will dine in Dublin with honorary consul-general Alan McCarthy and High Commissioner Sir Lockwood Smith, before touring the Irish and Northern Irish parliaments and visiting the birthplace of former New Zealand Prime Minister John Ballance.
The following week they will meet the Polish Deputy Prime Minister, Janusz Piechocinski, in Warsaw and visit the royal castle and Wawel Cathedral in Krakow. MPs will then visit the Auschwitz death camp before travelling on to Munich and Berlin for further meetings with officials and dignitaries.
Mr Carter said the New Zealand delegation would "exchange views on the significant economic, political and security challenges in the European Union and its near neighbourhood, as well as those affecting the Pacific."
The statement continued: "The delegation will also discuss and learn each country's perspectives on recent developments within the EU, particularly for European economies and in the area of immigration."
