Trecina Anderson was appointed as an associate in missions to the country of Spain in 2003 and served eight years under the missionary supervision of Gary Sones. There she served as missions promoter, Bible shcool teacher, sub-coordinator for the English ministry, assisted with administration in the national office and inititated four new departments in the local church in Madrid. During these years she preached both in Spain and in her travels in the United States. In October 2011, she was appointed UPCI missionary to the country of Spain where she continued to serve. In October 2015, Sister Trecina's missionary appointment was changed to Portugal where she has pioneered two churches in southern Portugal. She has taught in the Bible school as well as working with the national board. On her return to Portugal, she hopes to increase efforts to plant more churches in the Algarve Region of Portugal and expand the community outreach programs to include a language school and a soup kitchen.