# Restrictions for using partial fractions

When given a fraction with both numerator and denominator as polynomials, and where the denominator is expressed as a multiplication of factors. Can we always use the partial fractions method for splitting the overall fraction into several fractions. Or do restrictions exist for using this method, e.g The degree of the numerator must be less than the degree of the denominator, or the factors in the denominator must have real coefficients?

You can find the more general statement (for polynomials over an arbitrary field $K$) here.