We study ℵ₀-stable theories, and prove that if T either has eni-DOP or is eni-deep, then its class of countable models is Borel complete. We introduce the notion of λ-Borel completeness and prove that such theories are λ-Borel complete. Using this, we conclude that an ℵ₀-stable theory satisfies $I_{\infty ,\aleph ₀}(T,\lambda )=2^{\lambda }$ for all cardinals λ if and only if T either has eni-DOP or is eni-deep.