What the marginal lending rate is
The marginal lending facility lets a bank borrow overnight from its national central bank, on its own initiative and at any time, provided it pledges enough eligible collateral. The marginal lending rate is what that overnight loan costs. The ECB sets out how the facility works on its page on standing facilities: the two standing facilities provide and absorb overnight liquidity and bound overnight market rates.
Together with the deposit facility rate, it forms a corridor. A bank with spare money will not lend overnight for less than the deposit facility pays, and a bank short of money will not pay more than the marginal lending rate, because it can always borrow from the central bank at that price instead. The main refinancing rate sits inside the corridor.
The Governing Council sets all three at its monetary policy meetings, about every six weeks, and a change takes effect on a later date, usually the following Wednesday. The width of the corridor is itself a decision: on 9 October 2008, in the middle of the financial crisis, it was narrowed from 200 to 100 basis points around the main refinancing rate, and since 11 June 2014 the marginal lending rate has stood 25 basis points above the main refinancing rate. The statement of 13 March 2024 on the operational framework narrowed the gap below the main refinancing rate but left this 25-point gap above it in place.
Why it rarely touches your loan
You will not find a mortgage or a savings account priced from the marginal lending rate. Its job is to stop overnight rates spiking when a bank is short of funds at the end of a day, and in the years of plentiful reserves banks have had little reason to use it. Overnight market rates have traded close to the floor of the corridor, not the ceiling.
What it does tell you is that the corridor has moved. Because the three rates move together, a change here is a change in the deposit facility rate and the main refinancing rate too, and those are the rates that reach euro mortgages and savings through Euribor and longer-term market rates. For what a decision means for a loan in your country, read the deposit facility rate page and the mortgage tracker for your country, such as Germany or Spain.
Reading the chart and the table
The chart draws the rate as steps, and each point is a date a change took effect, as the ECB records it in its table of key interest rates. The ECB's own series has a row on every date any of the three key rates changed; where only another rate moved, this page leaves the date out, so every point here is a change in this rate.
The first point is the rate set for the euro's launch on 1 January 1999. For three weeks after that the ECB ran a temporarily narrow corridor to ease the changeover, which shows as a fall and a rise within January 1999. October 2008 has two changes a day apart: the coordinated cut of 8 October and the narrowing of the corridor that took effect the next day. The CSV download carries the ECB's own dates and values.