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  <xsd:element name="CommercialRealEstateFarmlandAndCommercialReceivableMember" id="iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ResidentialFirstMortgageFinancingReceivableMember" id="iboc_ResidentialFirstMortgageFinancingReceivableMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ResidentialSecondMortgageFinancingReceivableMember" id="iboc_ResidentialSecondMortgageFinancingReceivableMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ForeignReceivablesMember" id="iboc_ForeignReceivablesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="CommercialRealEstateMultifamilyReceivableMember" id="iboc_CommercialRealEstateMultifamilyReceivableMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="LoansReceivableCommercialFinancialAndAgriculturalMember" id="iboc_LoansReceivableCommercialFinancialAndAgriculturalMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="SpecialPassMember" id="iboc_SpecialPassMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="IncentiveStockOptionsTo10PercentShareholdersMember" id="iboc_IncentiveStockOptionsTo10PercentShareholdersMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="BondMeetingOriginalContractTermsMember" id="iboc_BondMeetingOriginalContractTermsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="BondNotMeetingOriginalContractTermsMember" id="iboc_BondNotMeetingOriginalContractTermsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="DocumentAndEntityInformationAbstract" id="iboc_DocumentAndEntityInformationAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="InterestExpenseOtherBorrowings" id="iboc_InterestExpenseOtherBorrowings" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="OtherServiceChargesCommissionsAndFeesAbstract" id="iboc_OtherServiceChargesCommissionsAndFeesAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ServiceChargesFeesAndCommissionsOtherBanking" id="iboc_ServiceChargesFeesAndCommissionsOtherBanking" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="OtherThanTemporaryImpairmentLossesInvestmentPortionRecognizedInEarningsNet" id="iboc_OtherThanTemporaryImpairmentLossesInvestmentPortionRecognizedInEarningsNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="AccretionOfDiscountsInvestments" id="iboc_AccretionOfDiscountsInvestments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="AmortizationOfInvestmentSecuritiesPremiums" id="iboc_AmortizationOfInvestmentSecuritiesPremiums" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="DistributionsFromOtherInvestments" id="iboc_DistributionsFromOtherInvestments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="IncreaseDecreaseInNoninterestBearingDemandDeposits" id="iboc_IncreaseDecreaseInNoninterestBearingDemandDeposits" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="IncreaseDecreaseInSavingAndInterestBearingDemandDeposits" id="iboc_IncreaseDecreaseInSavingAndInterestBearingDemandDeposits" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <element id="iboc_InvestmentSecuritiesPurchasesNotYetSettled" name="InvestmentSecuritiesPurchasesNotYetSettled" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xsd:element name="BasisOfPresentationDisclosureAbstract" id="iboc_BasisOfPresentationDisclosureAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="BasisOfPresentationTextBlock" id="iboc_BasisOfPresentationTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="AllowanceForProbableLoanLossesDisclosureAbstract" id="iboc_AllowanceForProbableLoanLossesDisclosureAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OtherBorrowedFundsDisclosureAbstract" id="iboc_OtherBorrowedFundsDisclosureAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfJuniorSubordinatedBorrowingsTableTextBlock" id="iboc_ScheduleOfJuniorSubordinatedBorrowingsTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="NumberOfActiveOperatingSubsidiaries" id="iboc_NumberOfActiveOperatingSubsidiaries" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ImpairedFinancingReceivableRecordedInvestmentFairValueDisclosure" id="iboc_ImpairedFinancingReceivableRecordedInvestmentFairValueDisclosure" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="ImpairedCommercialCollateralFinancingReceivableAppraisalsToDetermineFairValue" id="iboc_ImpairedCommercialCollateralFinancingReceivableAppraisalsToDetermineFairValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="OtherRealEstateAndForeclosedAssetsInUse" id="iboc_OtherRealEstateAndForeclosedAssetsInUse" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="FairValueMeasurementsDiscountedCashFlowModelAssumptionsFuturePrincipalPrepaymentRatesLowEndOfRange" id="iboc_FairValueMeasurementsDiscountedCashFlowModelAssumptionsFuturePrincipalPrepaymentRatesLowEndOfRange" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" />
  <xsd:element name="FairValueMeasurementsDiscountedCashFlowModelAssumptionsFuturePrincipalPrepaymentDiscountRate" id="iboc_FairValueMeasurementsDiscountedCashFlowModelAssumptionsFuturePrincipalPrepaymentDiscountRate" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" />
  <xsd:element name="FairValueMeasurementsDiscountedCashFlowModelAssumptionsLossSeverityRatesForFirstYear" id="iboc_FairValueMeasurementsDiscountedCashFlowModelAssumptionsLossSeverityRatesForFirstYear" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" />
  <xsd:element name="FairValueMeasurementsDiscountedCashFlowModelAssumptionsLossSeverityRatesThereafter" id="iboc_FairValueMeasurementsDiscountedCashFlowModelAssumptionsLossSeverityRatesThereafter" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" />
  <xsd:element name="ChangeInProvisionOfImpairedFinancingReceivableFairValueDisclosure" id="iboc_ChangeInProvisionOfImpairedFinancingReceivableFairValueDisclosure" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="ChangeInProvisionOfOtherRealEstateAndForeclosedAssetsInUse" id="iboc_ChangeInProvisionOfOtherRealEstateAndForeclosedAssetsInUse" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="AllowanceForLoanLeaseLossesWriteOffsPriorToForeclosure" id="iboc_AllowanceForLoanLeaseLossesWriteOffsPriorToForeclosure" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="FairValueMeasurementsDiscountedCashFlowModelAssumptionsDeclineInLossSeverityRatesForFollowingFifthYear" id="iboc_FairValueMeasurementsDiscountedCashFlowModelAssumptionsDeclineInLossSeverityRatesForFollowingFifthYear" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="FairValueMeasurementsDiscountedCashFlowModelAssumptionsDefaultRates" id="iboc_FairValueMeasurementsDiscountedCashFlowModelAssumptionsDefaultRates" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" />
  <xsd:element name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossAbstract" id="iboc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TimeDepositsFairValueDisclosure" id="iboc_TimeDepositsFairValueDisclosure" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="LoansReceivableWithFixedRateOfInterestFairValueDisclosure" id="iboc_LoansReceivableWithFixedRateOfInterestFairValueDisclosure" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="SecuritiesSoldUnderLongTermAgreementsToRepurchase" id="iboc_SecuritiesSoldUnderLongTermAgreementsToRepurchase" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="ReceivablesFromDomesticOperationsMember" id="iboc_ReceivablesFromDomesticOperationsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsReductionsFromOutstandingAbstract" id="iboc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsReductionsFromOutstandingAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsReductionsFromOutstandingWeightedAverageExercisePriceAbstract" id="iboc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsReductionsFromOutstandingWeightedAverageExercisePriceAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueDisclosuresAbstract" id="iboc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueDisclosuresAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="AvailableForSaleSecuritiesPledgedAsCollateralAmortizedCost" id="iboc_AvailableForSaleSecuritiesPledgedAsCollateralAmortizedCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="NumberOfStatutoryBusinessTrustsIssuingPreferredSecurities" id="iboc_NumberOfStatutoryBusinessTrustsIssuingPreferredSecurities" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="MaximumNumberOfConsecutiveQuarterlyPeriodsAvailableForDeferralOfPaymentOfInterest" id="iboc_MaximumNumberOfConsecutiveQuarterlyPeriodsAvailableForDeferralOfPaymentOfInterest" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <element id="iboc_MaximumPercentageOfCapitalSecuritiesIssuedByTrustQualifyingAsTierOneCapital" name="MaximumPercentageOfCapitalSecuritiesIssuedByTrustQualifyingAsTierOneCapital" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="iboc_MinimumPercentageOfCapitalSecuritiesIssuedByTrustQualifyingAsTierTwoCapital" name="MinimumPercentageOfCapitalSecuritiesIssuedByTrustQualifyingAsTierTwoCapital" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="iboc_CapitalSecuritiesIssuedByTrustQualifyingAsTierOneCapital" name="CapitalSecuritiesIssuedByTrustQualifyingAsTierOneCapital" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="iboc_ClassOfWarrantOrRightTerm" name="ClassOfWarrantOrRightTerm" nillable="true" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xsd:element name="FairValueMeasurementsDiscountedCashFlowModelMinimumPerformancePeriodUnderOriginalTerms" id="iboc_FairValueMeasurementsDiscountedCashFlowModelMinimumPerformancePeriodUnderOriginalTerms" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsAdditionalCreditLossesAfterTax" id="iboc_OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsAdditionalCreditLossesAfterTax" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="AllowanceForLoanAndLeaseLossesPeriodIncreaseDecreaseLoansTransferredToOtherRealEstateOwned" id="iboc_AllowanceForLoanAndLeaseLossesPeriodIncreaseDecreaseLoansTransferredToOtherRealEstateOwned" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="DebtInstrumentsRedemptionPriceDiscount" id="iboc_DebtInstrumentsRedemptionPriceDiscount" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <element id="iboc_MaximumPercentageOfCashDividendsInExcess" name="MaximumPercentageOfCashDividendsInExcess" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xsd:element name="MandatoryComplianceTerm" id="iboc_MandatoryComplianceTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TrustTenAndElevenMember" id="iboc_TrustTenAndElevenMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TrustTenMember" id="iboc_TrustTenMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TrustTwelveMember" id="iboc_TrustTwelveMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TrustElevenMember" id="iboc_TrustElevenMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TrustSixMember" id="iboc_TrustSixMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TrustNineMember" id="iboc_TrustNineMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TrustEightMember" id="iboc_TrustEightMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <element id="iboc_StockRepurchaseProgramCumulativeSharesRepurchased" name="StockRepurchaseProgramCumulativeSharesRepurchased" nillable="true" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="iboc_StockRepurchaseProgramCumulativeCostOfSharesRepurchased" name="StockRepurchaseProgramCumulativeCostOfSharesRepurchased" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="iboc_AggregateCommonStockInvestmentAsPercentageOfSeniorPreferredStockInvestmentOnExerciseOfWarrants" name="AggregateCommonStockInvestmentAsPercentageOfSeniorPreferredStockInvestmentOnExerciseOfWarrants" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="iboc_CommonEquityTierOneRatio" name="CommonEquityTierOneRatio" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="iboc_PercentageOfAdvancesFromFederalHomeLoanBanksIncreaseDecrease" name="PercentageOfAdvancesFromFederalHomeLoanBanksIncreaseDecrease" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="iboc_ImpairedCollateralDependentCommercialLoansWithInternalEvaluationCompletedWithinLastTwelveMonths" name="ImpairedCollateralDependentCommercialLoansWithInternalEvaluationCompletedWithinLastTwelveMonths" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
</xsd:schema>
