We study anomalies in time-reversal (Z T 2 ) and U (1) symmetric topological orders. In this context, an anomalous topological order is one that cannot be realized in a strictly (2 + 1)-D system but can be realized on the surface of a (3 + 1)-D symmetry-protected topological (SPT) phase. To detect these anomalies we propose several anomaly indicators -functions that take as input the algebraic data of a symmetric topological order and that output a number indicating the presence or absence of an anomaly. We construct such indicators for both structures of the full symmetry group, i.e. U (1) Z T 2 and U (1) × Z T 2 , and for both bosonic and fermionic topological orders. In all cases we conjecture that our indicators are complete in the sense that the anomalies they detect are in one-to-one correspondence with the known classification of (3 + 1)-D SPT phases with the same symmetry. We also show that one of our indicators for bosonic topological orders has a mathematical interpretation as a partition function for the bulk (3 + 1)-D SPT phase on a particular manifold and in the presence of a particular background gauge field for the U (1) symmetry. * email address: mlapa@uchicago.edu † email address: malevin@uchicago.edu 1 In this paper, we only consider topological orders that can be realized on surfaces of (3 + 1)-D SPT phases, which by definition are short-range entangled. We do not address the question of which topological orders can be realized on the boundary of (3 + 1)-D long-range entangled phases. Readers interested in this topic can consult Ref. 14, for example. arXiv:1905.00435v1 [cond-mat.str-el] 1 May 2019