The invention concerns a method for detecting an underdosage of an analytical test element and optionally for compensating the underdosage. The invention also concerns an analytical system and a test element which are suitable for detecting an underdosage.An underdosage of the test element can be reliably detected and optionally calculated by irradiating the analytical test element in a control wavelength range. For this purpose the test element contains a control substance which interacts with the radiation in the control wavelength range as a function of the contact with the applied amount of sample.