Investment approach
Where to find the official Euribor and which value the bank will use
For a mortgage the daily Euribor on financial sites does not matter; the official monthly value from the Banco de España and then the BOE does. Where to find it and which month the bank applies.
Euribor is the eurozone's interbank rate, and for a mortgage in Spain what matters is the official index: the monthly average of the daily 12-month Euribor values, which EMMI (the European Money Markets Institute) calculates and the Banco de España publishes. For September 2026 it was 3.247%, 1.075 points higher than a year earlier (Banco de España, note of 1 October 2026). Official indices take effect from publication in the BOE (Spain's official gazette), usually a few days later.
How the official Euribor differs from the daily one
The daily Euribor value changes every business day and is shown on financial sites. A mortgage contract refers not to it but to the official index: the arithmetic mean of the daily values over the month. The Banco de España describes the one-year Euribor as the most widespread index for revising variable mortgages and states that it publishes the EMMI calculation (Banco de España, Cliente Bancario).
So the news "Euribor rose today" says almost nothing about the payment. The payment changes on the revision date according to the official value of the month named in the contract. How the index gets into the rate formula is covered in the article Euribor in plain words.
Where to find the official value
The official value is published in three places, and for the contract the last one matters.
- The Banco de España press release. It comes out in the first business days of the month for the previous month; the archive is collected on the interest-rate statistics page (Banco de España).
- The official-indices page in Cliente Bancario. The definitions of all the official rates and links to the rules are there too.
- The BOE. Official indices take effect from publication in the BOE, which usually happens a few days after the Banco de España distributes them.
The last twelve values from the Banco de España press-release archive:
| Month | 12-month Euribor, official |
|---|---|
| October 2025 | 2.187% |
| November 2025 | 2.217% |
| December 2025 | 2.267% |
| January 2026 | 2.245% |
| February 2026 | 2.221% |
| March 2026 | 2.565% |
| April 2026 | 2.747% |
| May 2026 | 2.804% |
| June 2026 | 2.798% |
| July 2026 | 2.855% |
| August 2026 | 2.954% |
| September 2026 | 3.247% |
What other official indices there are
The 12-month Euribor is not the only official index, and the contract may name another. The Banco de España publishes a family of indices; the values for September 2026 from the same note:
| Index | September 2026 |
|---|---|
| 1-week Euribor | 2.289% |
| 1-month Euribor | 2.414% |
| 3-month Euribor | 2.635% |
| 6-month Euribor | 2.922% |
| 5-year IRS | 3.450% |
| 1-year index based on the €STR | 2.034% |
The average rate on mortgages of more than three years for buying free-market housing in Spain, known as the IRPH, and the eurozone average rate are updated around the 20th in table 19.1 of the Boletín Estadístico (the Banco de España's statistical bulletin). For contracts where the old index has disappeared, the law provides for replacement by this average rate with a corrective adjustment, and the Banco de España offers a simulator to calculate it.
Which value the bank will take at revision
The bank takes the index value for the month named in the contract, not for the date of revision. The order for checking your own contract:
- Find in the escritura (notarial deed) the index, the spread and the frequency of revision.
- Find the wording on the index month: for example "último publicado" (the last one published) or the value for the month that precedes the revision by a set number of months.
- Find the fallback index in case the main one disappears.
- Check the bank's recalculation against the official value in the BOE.
Worked example, not a forecast. Spread 0.90%, revision on 1 December 2026, and the contract takes the last value published in the BOE before the revision date. If it is the September value, the rate for the next year is 3.247% + 0.90% = 4.147%. If it is October's, the rate will be recalculated from October's. The payment for your own amount and term is easy to check in the calculator.
When Euribor is not a useful guide for a mortgage
Watching the index is pointless if the mortgage is fixed: the rate does not change for the whole term. It is also of little use with a mortgage on the IRPH or another index: then its value is what counts, not Euribor. With a mixed mortgage Euribor starts to matter only after the fixed period. The differences between rate types are covered in the article on mortgage types, and the effect of rates on projects with refurbishment and sale in the piece on variable and fixed rates.
Questions and answers
Where can I see the official Euribor for the month?
In the Banco de España press release at the start of the following month, on the interest-rate statistics page and in the BOE. For the contract the value takes effect from publication in the BOE.
How does "today's" Euribor differ from what the bank takes?
The daily value changes every business day. The bank applies the official index, the average of the daily values over the month, and only for the month named in the contract.
What was Euribor in September 2026?
According to the Banco de España, the official 12-month Euribor for September 2026 was 3.247%, 1.075 points higher than in September 2025.
Are there mortgages on the 6-month Euribor or another index?
Yes. The official list includes the Euribor for one week, one month, three and six months, the 5-year IRS, indices based on the €STR and the IRPH average mortgage rate. Which one applies is stated in the contract.
What happens if the index in the contract stops being published?
The fallback index from the contract applies. If there is none or it has also disappeared, the law provides for replacement by the average rate on mortgages of more than three years with a corrective spread.
