Catalyzes the reversible phosphorylytic cleavage of uridine to uracil and ribose-1-phosphate which can then be utilized as carbon and energy sources or in the rescue of pyrimidine bases for nucleotide synthesis (PubMed:12849978, PubMed:21855639). Shows broad substrate specificity and can also accept deoxyuridine and other analogous compounds (PubMed:12849978). {ECO:0000269|PubMed:12849978, ECO:0000269|PubMed:21855639}. This is the function of ENSG00000007001 (UPP2, uridine phosphorylase 2).