We examine the choice of borrowing source between public debt, syndicated bank loans, bilateral bank loans, and non-bank private debt. Using a sample of 400 non-financial firms over 2000-2012, we find strong support for the reputational theory of borrowing source. Larger firms are more likely to borrow in public debt markets. Bank dependent firms are less likely to borrow in public debt markets and choose between bank and non-bank private debt based on maturity, collateral available to lenders, and other firm characteristics. These results are consistent with the role of borrower reputation being the primary determinant of borrowing source for UK listed firms.