This study investigated the occurrence of antimicrobial residues in bulk tank milk (BTM) from dairy herds in the Thrace region of Türkiye. A total of 122 samples were analysed using a broad-spectrum microbiological inhibition assay (BRT hi-sense) and a commonly used end-point screening test (Bioeasy 2IN1 BT) targeting β-lactams and tetracyclines. BRT-positive samples were further analysed using a Bioeasy 16IN1 multi-residue test. Antimicrobial residues were detected in 13 samples (11%) by BRT hi-sense, whereas no β-lactam or tetracycline residues were identified by the Bioeasy 2IN1 BT test. The 16IN1 test identified antimicrobial classes in 9 positive samples, with macrolides (n = 7) and sulfonamides (n = 4) most frequently detected. Two samples showed multiple antimicrobial residues. LC-MS/MS confirmed macrolide residues above maximum residue limits in selected two samples. These findings indicate limitations of mandatory end-point–based residue screening conducted at dairy plants in Türkiye and highlight the need for broader-spectrum screening to improve residue surveillance and milk safety.