Fertilizer samples are analyzed to ascertain their nutritional content; however, the results differ according on the technique employed. The study's main objective was to develop and evaluate an approach for measuring Copper using an atomic absorption spectrophotometer. Copper content in fertilizer samples was measured using the Atomic Absorption Spectrophotometer Technique, which was verified by Dera Ghazi Khan's Soil & Water Testing Laboratories. As part of the validation process approach, tests were conducted on selectivity, bias, linearity, recovery, detection limit, repeatability, linearity, and selectivity. The findings showed that the sample's LOD and LOQ values for Copper, as well as its repeatability (relative standard deviation of 4.98 and T-value 0.063 being less than the calculated T value of 2.0262), recovery of 97%. The Copper concentration's linear curve, which displayed linearity R2 = 0.998 %, was obtained between 0.5 mg Kg^-1 and 2.0 mg Kg^-1 (Cu). The laboratory took part in the Magruder Fertiliser Sample Check Programme, an American proficiency testing programme. The Z-score values of -0.39 of the Copper samples examined using this approach are within an acceptable range (i.e., -2 to +2). The method's uncertainty was ±0.026%. Therefore, Copper analysis using the recommended method in accordance with standard may be carried out at the Dera Ghazi Khan Soil and Water Testing Laboratory. This association leads us to the conclusion that the plan was effective.