The A330 MRTT's wing has common structure with the four-engine A340-200/-300 with reinforced mounting locations and provision for fuel piping for the A340's outboard engines.

The passenger cabin of the A330 MRTT can be provided with a set of removable airstairs to enable embarkation and disembarkation when jet bridges or ground support equipment are not available.

[4] The first delivered aircraft (the third to be converted) arrived in Australia on 30 May 2011 and was formally handed over to the Royal Australian Air Force (RAAF) two days later on 1 June.

The new standard features structural modifications, aerodynamic improvements for a 1% fuel-burn reduction, upgraded avionics computers, and enhanced military systems.

[6] An Airbus/Saab team proposed an A330-based Airborne early warning and control (AEW&C) ("AWACS") variant with Saab's Erieye radar to the UK's Ministry of Defence in 2018 for the replacement of its Boeing E-3 Sentry fleet.

[20] In August 2013, the KC-30A made its debut as a VIP transport, ferrying Prime Minister Kevin Rudd and an entourage to Al Minhad Air Base in the United Arab Emirates.

[22] In July 2015, Defence Minister Kevin Andrews announced the order of two additional KC-30s, to be converted from A330-200s previously operated by Qantas, for delivery in 2018.

[23][24] In 2016, the decision was made to add a modest VIP fitout, including seating, meeting spaces and communication facilities, to a single KC-30A,[25] which remains primarily used as a tanker.

[42] In June 2020, ZZ336 received a new livery based on the colours of the Union Flag at the request of the British Prime Minister Boris Johnson.

[67] The RSAF's six MRTTs attained full operational capability (FOC) on 20 April 2021 and currently fly with the 112 Squadron at Changi Air Base (East) in Singapore.

The ROKAF held a contest among their service members and chose the name 'Cygnus' after holding a deliberation committee session in November 2018 - January 2019.

[77] It extends the endurance of ROKAF aircraft over remote areas such as Dokdo, Ieodo, and the North Pyongyang-Wonsan Line, as well as increase its ability to deploy overseas for international operations.

[78][79] It is not only aerial refueling, but also serves as a transport aircraft for the deployment of personnel,[80] such as repatriation of remains from the Korean War,[81][82] replacement of overseas troops,[83] transfer of South Korean Iraqi residents due to COVID-19,[84] transportation of Janssen vaccines,[85] participated in Operation Oasis, which transfer of Cheonghae Unit members of the Munmu the Great when they contracted COVID-19,[86] repatriation of General Hong Beom-do's remains and return to South Korea,[87] participated in Operation Miracle, which transported cooperative Afghans,[88] sent to import Diesel exhaust fluid from Australia to ease a supply shortage of the key material used in diesel vehicles,[89] sent relief supplies and personnel to Turkey when the Turkey–Syria earthquake occurred,[90] supported Operation Promise, which allowed Koreans to escape when the Sudanese war broke out,[91] and helped fight Canadian wildfires[92] so Canadian Prime Minister Justin Trudeau made a surprise visit to thank them for this,[93] and the transportation of South Korean residents and travelers, 51 Japanese,[94] and 6 Singaporeans[95] in Israel due to the Israel-Hamas war.

[96] In November 2011, France expressed interest in acquiring 14 A330 MRTTs to replace its Boeing KC-135 tankers and Airbus A340 and A310 transports; one year later, it was announced that 14 would be ordered in 2013.

[99] On 20 February 2014, the French Chief of Staff stated that 12 A330 MRTTs would be acquired in two batches, an initial standard configuration with a boom and wing refuelling pods and later with a cargo door and SATCOM.

[105] On 13 December 2018, France ordered another three MRTTs of a third tranche of the multi-year contract; these are powered by Rolls-Royce Trent 700 engines and equipped with the ARBS and underwing hose-and-drogue refuelling pods.

[107] In November 2012, the Ministers of Defence of 10 EDA member states (the Netherlands, Belgium, France, Greece, Spain, Hungary, Luxembourg, Poland, Portugal and Norway) signed a letter of intent to jointly procure a multi-role tanker transport.

The Netherlands was designated leader of the newly launched Multinational Multi-Role Tanker Transport Fleet (MMF) project, which had the aim of creating an initial European AAR capability by 2020.

[107] In 2013, the Netherlands expressed interest in the A330 MRTT to replace its two KDC-10 aircraft; a study was launched on standardising European AAR capability in cooperation with other MFF members.

[107] This was accompanied by a request for proposals sent by OCCAR to Airbus for two MRTTs with options for six more; only the Netherlands and Luxembourg were full MMF members at this point.

[138] In September 2020, Spain agreed to buy from Iberia three A330s no longer needed due to the economic impact of the COVID-19 pandemic, then modify them to serve as a MRTT fleet.

[146] On 27 January 2022, the Brazilian Air Force ended negotiations with the RAF and launched international bidding to buy two A330-200s on the civil market, estimated at US$81 million.

[152] In April 2021, Airbus was declared the only qualified supplier to replace Canada's RCAF CC-150 Polaris refuelling and VIP transport aircraft, beating out Boeing's KC-46 Pegasus.

[165] In January 2018, the IAF re-launched its aerial refuelling procurement programme, sending out a request for information (RFI) to Airbus, Boeing and Ilyushin.

[170][171] A consortium of Lockheed Martin and Airbus was proposing a variant called LMXT for the Bridge Tanker Competition referred to as KC-Y, which could lead to a contract to build up to 160 aircraft.

[179] The US Air Force (USAF) ran a procurement programme to replace around 100 of its oldest KC-135E Stratotankers, i.e., initially excluding the more common updated KC-135R variant.

[188][189] On 18 June 2008, the United States Government Accountability Office (GAO) upheld a protest by Boeing on the contract's award to Northrop Grumman and EADS over process improprieties.

William J. Lynn III, the deputy defence secretary, said Boeing was "the clear winner" under a formula that considered the bid prices, how well each tanker met needs and the operating costs over 40 years.

[49] Following the incident, the Instituto Nacional de Técnica Aeroespacial, Spain's airworthiness authority, issued precautionary restrictions to other users of boom-equipped A330s.

[49] On 9 February 2014, a Royal Air Force A330 MRTT Voyager carrying 189 passengers and 9 crew from RAF Brize Norton to Camp Bastion suddenly lost 4,440 ft (1,350 m) of altitude in 27 seconds and reaching a maximum descent rate of 15,000 ft/min (4,600 m/min) while the co-pilot was out of the cockpit.