The smaller A220-100 (formerly CS100) first flew on 16 September 2013, received an initial type certificate from Transport Canada on 18 December 2015, and entered service on 15 July 2016 with launch operator Swiss Global Air Lines.

[19] Bombardier announced on 31 January 2006 that market conditions could not justify the launch of the program, and that the company would reorient CSeries project efforts, team and resources to regional jet and turboprop aircraft.

[22] Bombardier's Board of Directors authorized offering formal sales proposals of the CSeries to airline customers on 22 February 2008, due to its 20% lower fuel burn and up to 15% better operating costs compared to similarly sized aircraft produced at the time.

[23] In a press conference on the eve of the opening of the Farnborough Airshow on 13 July, Bombardier Aerospace formally launched the CSeries, with a letter of interest from Lufthansa for 60 aircraft, including 30 options, at a US$46.7 million list price.

[35] In November 2011, Bombardier expected a second-half 2012 first flight as it wasn't to receive the first fuselage package until mid-2012 at the earliest and Pratt & Whitney still had "a little bit more work to do" to meet the requirement.

[38] In July 2012, Bombardier began discussions with AirAsia at the Farnborough Airshow about a 160-seat high-density CS300 concept,[39] which was subsequently added to the CSeries program in November, despite the low cost airline's refusal to order 100 units of this version.

[40] In the same month, Bombardier announced a six-month delay in both the first flight to June 2013 and the entry into service (EIS) of the CS100 a year later due to unspecified supplier issues in some areas of the program.

[65] The largest model, the 130- to 145-seat CS300, obtained its type certificate from Transport Canada on 11 July 2016,[66] from the EASA on 7 October that cleared the delivery to its launch operator airBaltic,[67] and from the FAA on 14 December 2016.

[2][74] The launch operator stated in August, that "the customer feedback is very positive with the expected remarks concerning the bright cabin, reduced noise, enough leg room and space for hand luggage as well as the comfortable seats.

[82] On 8 August, following the steep approach certification by EASA, Swiss operated its first revenue flight from Zurich to London City, replacing the Avro RJ.

[83] On 22 December, after months of engine delivery delays, Korean Air became the third and latest operator of CSeries after receiving its first CS300,[87][88] and completed its first revenue flight from Seoul to Ulsan on 20 January 2018.

Financial issues at Bombardier due to the CSeries programme and production delays, stiff competition and ultimately a dumping petition by Boeing paved the way for the partnership.

[125] Embraer assured at the Dubai Airshow in November 2017 that its base country Brazil would sue Canada for its subsidies to Bombardier through the World Trade Organization,[126] because the competitor viewed CSeries as a heavy, expensive, and long, thin-haul aircraft outperforming the range of its own E-Jet E2, a close rival for market share.

[127] Then, in December 2017, The Wall Street Journal reported Boeing was planning to offer Embraer more than the company's $3.7 billion market value to set up a joint venture,[128] in what aviation industry analysts said was a reaction to the partnership.

[129] The Boeing–Embraer joint venture was announced in February 2019, but before the antitrust investigations were completed, the deal was unilaterally terminated by Boeing in April 2020 due to impact of the 2019–20 coronavirus pandemic on aviation.

[130] The antitrust investigation was due to be completed ahead of Farnborough Airshow 2018 to allow for a marketing boost,[131] and it was planned to rebrand the CSeries as an Airbus model, with A200 suggested as a family name and A210/A230 for the CS100 and CS300.

[142] Under the latest agreement in July 2024 the threshold for Airbus to buy out Québec's share will be further extended to 2035,[143] securing that two-thirds of the jobs linked to the production of the A220 will remain in Quebec.

[206] The new A220 Airspace XL bins would be available and retrofittable from 2025, offering up to 19 additional passenger bags on the A220-300 and accommodating longer and heavier payload items thanks to the four-frame design.

[202] After successfully entering commercial service as the CSeries for two years in 2016, performing above its original specifications and receiving positive feedback from customers in Europe and Asia, the only airliner purpose-built for the 100-150 market seats[199] has expanded its operations worldwide to America, Africa and Australia as the A220 following the Airbus partnership.

[202] By July, the launch operator, Swiss Air Lines successfully completed C checks on its A220 fleet, performed by SAMCO Aircraft Maintenance in its MRO facilities at Maastricht Airport.

The A220's features made it popular with airlines, as they preferred smaller aircraft with similar range and economic performance as larger ones, in order to keep the load factor high enough.

[231] On 29 September 2021, Air France, the largest A220 customer in Europe, received its first A220-300 from an order for 60 aircraft, to be operated on the airline's medium-haul network with a 148 passengers single-class cabin.

[232] From August 2020 to July 2021, the A220 average on-time performance (OTP) was 99%, led by Korean Air with 99.63%, giving the airline the "Airbus A220 Best Operational Excellence 2021" award on 4 October 2021, during IATA's Annual General Meeting.

[240] In October, a batch of A220-300s originally destined for Russian airline Azimuth were delivered to ITA Airways (Italia Trasporto Aereo), the new Italian flag carrier, instead by their lessor.

[246] In July, five years after the A220 joined the Airbus aircraft family, the fleet of more than 260 A220s had flown over a billion kilometers on more than 1,100 routes ranging from 30 minutes to 8 hours, carrying more than 90 million passengers to over 375 destinations across the globe.

[247][248] The islands' flag carrier nicknamed its new fleet member the 'Cyprus Airways Greenliner' as the A220 is to reduce the company's emissions by around 40%,[249] and put it into service on 9 August with a flight from Larnaca to Athens.

[251] On 16 December, Qantas Group's domestic subsidiary QantasLink took delivery of its first A220-300 of 29 units on order, making it the 20th operator of the type, which would serve metropolitan and regional destinations across Australia.

[75] After four months of service with Swiss, this goal seemed to have been met based on only three aircraft and 1,500 hours flown; "nuisance messages" from the integrated avionics suite and engine start-up delays had been the main griefs.

[82] After three inflight engine failures in 2019, Transport Canada issued an emergency airworthiness directive (EAD) limiting the power to 94% of N1 (Low Pressure Spool rotational speed) above 29,000 ft (8,800 m), disengaging the autothrottle for the climb over this altitude before engaging it again in cruise.

[1] Since 2020, the Airbus A220 has also been available as a business jet (bizjet) under the name ACJ TwoTwenty, which is a variant of the A220-100 with a range of 5,650 nmi (10,460 km) and customisable cabin space of 73 m2 (790 sq ft) for 18 passengers.