We develop a new dataset of bank-level balance sheets data to estimate bank-level funding costs. These estimates are useful for monitoring funding pressures and other risks to the banking sector as well as understanding the impact of prudential regulations and market conditions on the transmission of monetary policy. We show that bank funding cost spreads are materially higher now than before the Global Financial Crisis of 2008, in spite of lower interest rates. We show that during the COVID-19 crisis, aggregate funding costs have fallen in level (i.e. percentage) terms, but that funding costs have increased when expressed relative to reference rates. We show that the relative cost of raising deposits has increased, as deposit rates have not fallen by as much as the repurchase rate and other money market rates.