[en] Highlights: • V²⁺/V³⁺ mixed valence states in AV₁₀O₁₅ (A = Ba, Sr) and Ba_0.9Sr_0.1V₁₃O₁₈ are studied by core level x-ray photoelectron spectroscopy (XPS). • In BaV₁₀O₁₅ and Ba_0.9Sr_0.1V₁₃O_18, the surface state has more V³⁺ than the bulk. • The evaluation of V²⁺/V³⁺ intensity ratio depends on the number of Gaussians/Voigts used in V 2p spectra. - Abstract: We have studied the surface electronic structure of AV₁₀O₁₅ (A = Ba, Sr) and Ba_0.9Sr_0.1V₁₃O₁₈ by using x-ray photoemission spectroscopy (XPS). The V 2p XPS shows multiple peaks associated with the charge fluctuation in the system. The relative intensity of each valence component can be extracted by Gaussian and Voigt fittings. The result strongly depends on the number of Gaussians/Voigts. In BaV₁₀O₁₅ and Ba_0.9Sr_0.1V₁₃O_18, the surface state has more V³⁺ than the bulk. In addition to the presence of surface V³⁺, the V^2.5+ in AV₁₀O₁₅ (A = Ba, Sr) and V²⁺ in Ba_0.9Sr_0.1V₁₃O₁₈ systems are observed even in the surface sensitive XPS. The number of Gaussians/Voigts should be as large as four for the V 2p_3/2, in order to obtain the results consistent with the bulk sensitive HAXPES study.