Euribor (Euro Interbank Offered Rate) is the benchmark interest rate at which European banks lend to one another and is widely used as the reference for variable‑rate mortgages in Portugal. Changes affect monthly payments directly: the recent figures reported were 2.034% (3‑month), 2.104% (6‑month) and 2.255% (12‑month), so a rising Euribor typically increases costs for borrowers with tracker or variable loans.