51 A1B : 440 : 44 M109A1B : 15 A0 : 12 : 224 (upgraded to M109 KAWEST) : 40 (from Switzerland) M109A2/A3 : 40 A3 (former Belgian) : 84 A2, 50 A3GEA1, 223 A3GEA2 : 400 A2 : 356 A2/A2-90 (121 M109A2-90 purchased from Netherlands) : 12 A3 : 78 M109A2, 22 M109A3 and 40 M-109L47 : 785 A2 in service with the Pakistan Army. Being upgraded to M109A5 standard. : 6 A2 in 2022 : 60 A2s are currently being upgraded to A5s (2010) : 6 (Spanish Marines) : 19–20 A2 (former Belgian) : 22 A3GN (donated by Norway) M109A2/A5 : 33 A2/A5Ö : 59 A5Ö (Taiwan): 197 : 6 units, previously owned by Latvia M109A4 : 36 units M109A4-BE bought from Belgium : 4 M109A4 : 28 units, previously owned by Belgium, bought, refurbished and donated by the UK. M109A5 : 96 A5/A5+ More 56 surplus U.S. Army, to be upgraded to M109A5+, contract awarded to BAE Systems. : 48 (24 from Switzerland, upgraded to M-109 KAWEST, 12 A3 and 12 A5+ Upgrade to similar Paladin configuration) : 201 : 36 : 90 : 600 : ca. 115 in 2022 : 18 since 2002 (Portuguese Army). 6 of these vehicles were M109A2/A3 upgraded to A5 variant. This variant replaced the previous 6 M109A2 operated by the Portuguese Army. : 20 : 12 : 96 (Spanish Army) : 70 : 74 TBD (Taiwan): 28 M109A6 Paladin : ca. 514 in service + ca. 850 in storage in 2022 : 177 ordered in April 2018. (Taiwan) (Cancelled): >100 planned in 2019, 40 approved by U.S. State Department in August 2021. However, the US has since cancelled the order, possibly in the wake of ramping up support for Ukraine, forcing Taiwan to consider alternative options. : 18 (pledged by the US) M109A7 : 48 with a further 180 contracted options K55/K55A1 : 1,180 K55s were produced by Samsung Aerospace Industries between 1985 and 1996. All vehicles are undergoing upgrade to K55A1 since 2010. Operated by the Army and the Marine Corps. Former operators M109A2/A3 : 167 A2, of which 64 were upgraded to the -A4BE standard, 31 sold to Brazil (1999–2001), 43 sold to Morocco (2008), the remainder sold to private companies in 2015. : 2–6 (upgraded to M109 A3DK, used to be 76) : 570 A3GE A1/A2, phased out by 1 July 2007 and replaced by the PzH 2000