12-month Euribor – September 2023
The average 12-month Euribor for September 2023 is 4.149 %, computed from 21 daily fixings (complete). The month opened at 4.055 %, closed at 4.228 %, with a low of 4.049 % and a high of 4.228 %. Versus August 2023 the average is up +0.076 pp.
Most variable mortgages in the euro area are revised on the monthly average, not the daily value. A loan that resets in September on the 12-month Euribor plus 1 pp would pay 5.15 % for the coming period.
Every number on this page is an official published fixing, not an estimate: daily values are the Euribor fixings as published in the ECB / Eurosystem's official statistics, monthly averages are the arithmetic mean of those fixings and are cross-checked against the ECB Data Portal, and the tables are refreshed every business day after the previous day's fixing appears. Tenors use the ACT/360 convention. Where a monthly average differs from the ECB figure by more than a hundredth of a point the methodology page lists the case.
What does it mean for a mortgage?
Annuity formula; assumes the rate applies for the whole remaining term. Your bank may round or use a different convention.
September 2023
Source: official ECB / Eurosystem data. Published with a 24-hour delay.
Date
| Date | Rate | Change |
|---|---|---|
| 4.228 % | +0.007 pp | |
| 4.221 % | +0.021 pp | |
| 4.200 % | +0.001 pp | |
| 4.199 % | -0.009 pp | |
| 4.208 % | -0.005 pp | |
| 4.213 % | -0.011 pp | |
| 4.224 % | +0.002 pp | |
| 4.222 % | +0.006 pp | |
| 4.216 % | +0.025 pp | |
| 4.191 % | +0.022 pp | |
| 4.169 % | +0.010 pp | |
| 4.159 % | +0.047 pp | |
| 4.112 % | +0.009 pp | |
| 4.103 % | +0.022 pp | |
| 4.081 % | -0.005 pp | |
| 4.086 % | +0.008 pp | |
| 4.078 % | +0.027 pp | |
| 4.051 % | -0.017 pp | |
| 4.068 % | +0.019 pp | |
| 4.049 % | -0.006 pp | |
| 4.055 % | – |
Source: official ECB / Eurosystem data. Published with a 24-hour delay.
Frequently asked questions
What is the 12-month Euribor average for September 2023?
4.149 %, computed from 21 daily fixings. The ECB's official monthly average is 4.149 %.
My mortgage revises with the September average – what rate applies?
Reference 4.149 % plus your contractual spread; with a 1 pp spread the new rate is 5.15 %. Check whether your contract uses the previous month or the month before that.
Source: official ECB / Eurosystem data. Published with a 24-hour delay. 07/09/2026