diff --git a/crates/immo-core/src/loan_offer.rs b/crates/immo-core/src/loan_offer.rs
index 1e194db..3ac886a 100644
--- a/crates/immo-core/src/loan_offer.rs
+++ b/crates/immo-core/src/loan_offer.rs
@@ -11,8 +11,23 @@ pub enum LoanOfferError {
     ZeroLoanDuration,
     #[error("borrowed capital should be strictly positive: {0}")]
     NonPositiveBorrowedCapital(Euros),
+    #[error("borrowed capital should be lower than {MAX_BORROWED_CAPITAL}: {0}")]
+    MaxBorrowedCapitalExceeded(Euros),
+    #[error("annual nominal rate should be lower than {MAX_ANNUAL_NOMINAL_RATE}: {0}")]
+    MaxAnnualNominalRateExceeded(Decimal),
+    #[error("loan duration in months should be lower than {MAX_LOAN_DURATION_IN_MONTHS}: {0}")]
+    MaxLoanDurationExceeded(u64),
 }
 
+/// 1b€ is a pretty expensive house...
+pub const MAX_BORROWED_CAPITAL: Euros = Euros::from_cents_as_i64(999_999_999_99);
+
+/// 99% nominal rate will hopefully never happen
+pub const MAX_ANNUAL_NOMINAL_RATE: Decimal = Decimal::from_parts(99, 0, 0, false, 2);
+
+/// Loan duration is theoretically constrained to max 25y in France, let's use 40 to be sure
+pub const MAX_LOAN_DURATION_IN_MONTHS: u64 = 40 * 12;
+
 #[derive(Debug, PartialEq, Eq)]
 pub struct LoanOffer {
     borrowed_capital: Euros,
@@ -28,10 +43,20 @@ impl LoanOffer {
     ) -> Result<Self, LoanOfferError> {
         if annual_nominal_rate < Decimal::ZERO {
             Err(LoanOfferError::NegativeInterestRate(annual_nominal_rate))
+        } else if annual_nominal_rate > MAX_ANNUAL_NOMINAL_RATE {
+            Err(LoanOfferError::MaxAnnualNominalRateExceeded(
+                annual_nominal_rate,
+            ))
         } else if loan_duration_in_months == 0 {
             Err(LoanOfferError::ZeroLoanDuration)
+        } else if loan_duration_in_months > MAX_LOAN_DURATION_IN_MONTHS {
+            Err(LoanOfferError::MaxLoanDurationExceeded(
+                loan_duration_in_months,
+            ))
         } else if borrowed_capital <= Euros::from_cents_as_i64(0) {
             Err(LoanOfferError::NonPositiveBorrowedCapital(borrowed_capital))
+        } else if borrowed_capital > MAX_BORROWED_CAPITAL {
+            Err(LoanOfferError::MaxBorrowedCapitalExceeded(borrowed_capital))
         } else {
             Ok(LoanOffer {
                 borrowed_capital,
@@ -77,6 +102,48 @@ mod tests {
         );
     }
 
+    #[test]
+    fn creating_loan_offer_with_borrowed_capital_higher_than_max_borrowed_capital_returns_max_borrowed_capital_exceeded_error()
+     {
+        let euros = MAX_BORROWED_CAPITAL + Euros::from_cents_as_i64(1);
+        let ret = LoanOffer::new(euros, Decimal::new(45, 2), 25);
+        assert_eq!(ret, Err(LoanOfferError::MaxBorrowedCapitalExceeded(euros)));
+    }
+
+    #[test]
+    fn creating_loan_offer_with_annual_nominal_rate_higher_than_max_annual_nominal_rate_returns_max_annual_nominal_rate_exceeded_error()
+     {
+        let annual_nominal_rate = MAX_ANNUAL_NOMINAL_RATE + Decimal::new(1, 2);
+        let ret = LoanOffer::new(
+            Euros::from_cents_as_i64(100_000_00),
+            annual_nominal_rate,
+            25,
+        );
+        assert_eq!(
+            ret,
+            Err(LoanOfferError::MaxAnnualNominalRateExceeded(
+                annual_nominal_rate
+            ))
+        );
+    }
+
+    #[test]
+    fn creating_loan_offer_with_loan_duration_higher_than_max_loan_duration_returns_max_loan_duration_exceeded_error()
+     {
+        let loan_duration_in_months = MAX_LOAN_DURATION_IN_MONTHS + 1;
+        let ret = LoanOffer::new(
+            Euros::from_cents_as_i64(100_000_00),
+            Decimal::new(314, 4),
+            loan_duration_in_months,
+        );
+        assert_eq!(
+            ret,
+            Err(LoanOfferError::MaxLoanDurationExceeded(
+                loan_duration_in_months
+            ))
+        );
+    }
+
     #[test]
     fn creating_loan_offer_with_null_borrowed_capital_returns_non_positive_borrowed_capital_error()
     {