Readability and the study of complexity of functional texts are of interest to many contemporary researchers. Nowadays, in the age of miniaturization, simplification of our everyday life components, portability, and domination of short text forms in the mass media, we can observe a decrease in interest in reading larger texts or those containing specialized, difficult to understand vocabulary. This is how consumer contracts (including insurance contracts) are perceived. The purpose of this article is, therefore, to examine and evaluate the readability of the General Insurance Terms and Conditions (hereinafter referred as: Insurance GTC) — an integral part of the insurance contract. In order to determine whether the language of the Insurance GTC is easy to understand, precise and clear for consumers, a quantitative and qualitative analysis was carried out using readability formulas, in particular FOG-PL — fully adapted to the specificity of the Polish language. The Insurance GTC corpus from four different insurance groups was examined, and its level of language “fogginess” was compared with other utility texts.