In this work, we present spectroscopic investigation of charge carriers in copper(II) salen-type polymeric complexes. The polymers comprising monomeric complexes of copper(II) ion with N2O2 Schiff base ligands are analyzed to understand the influence of the paramagnetic metal center and electron-donating substituents in the ligand on the spectroscopic properties of oxidized polymers. Potential-driven structural changes in the polymeric complexes were monitored using electron spin resonance (ESR), ultraviolet−visible − near infrared (UV−vis − NIR) and Fourier Transform Infrared (FTIR) spectroelectrochemistry. By EPR spectroelectrochemistry, we gained insight into the magnetic properties of charge carriers formed during the initial and deep oxidation of the polymers as well as the interactions between the Cu(II)–ligand spins and ligand–ligand ones. By FTIR spectroelectrochemistry, it has been shown that the charge in the low doped polymers is delocalized within the whole repeat unit.