diff --git a/specification/billingbenefits/BillingBenefits.Management/back-compatible.tsp b/specification/billingbenefits/BillingBenefits.Management/back-compatible.tsp
index 10cc65a544a0..0af15f58b700 100644
--- a/specification/billingbenefits/BillingBenefits.Management/back-compatible.tsp
+++ b/specification/billingbenefits/BillingBenefits.Management/back-compatible.tsp
@@ -5,7 +5,7 @@ using Microsoft.BillingBenefits;
 
 // @@clientLocation and @@clientName decorators for operations that originally had @operationId
 // All @operationId decorators have been removed and replaced with these client customizations
-@@clientLocation(SavingsPlanOperationGroup.listAll, "SavingsPlan");
+@@clientLocation(SavingsPlanOperationGroup.listAll, "SavingsPlan", "!csharp");
 
 @@clientLocation(DiscountsOperationGroup.scopeList, Discounts);
 @@clientLocation(ReservationOrderAliasResponses.get, "ReservationOrderAlias");
diff --git a/specification/billingbenefits/BillingBenefits.Management/client.tsp b/specification/billingbenefits/BillingBenefits.Management/client.tsp
index 30b3c972ffa9..d375fd05663e 100644
--- a/specification/billingbenefits/BillingBenefits.Management/client.tsp
+++ b/specification/billingbenefits/BillingBenefits.Management/client.tsp
@@ -4,46 +4,317 @@ import "@azure-tools/typespec-client-generator-core";
 using Azure.ClientGenerator.Core;
 using Microsoft.BillingBenefits;
 
-// go
-@@clientLocation(BenefitOperationGroup.validate, "RP", "go");
-@@clientName(Microsoft.BillingBenefits.ResourceSku, "SKU", "go");
 @@clientName(
   Microsoft.BillingBenefits.ManagedServiceIdentity,
   "ServiceManagedIdentity",
-  "go"
+  "go,java,python,javascript"
 );
 @@clientName(
   Microsoft.BillingBenefits.ManagedServiceIdentityType,
   "ServiceManagedIdentityType",
-  "go"
+  "go,java,python,javascript"
 );
 
+// go
+@@clientLocation(BenefitOperationGroup.validate, "RP", "go");
+
 // java
 @@clientLocation(BenefitOperationGroup.validate, "ResourceProviders", "java");
+
+// csharp
 @@clientName(
   Microsoft.BillingBenefits.ManagedServiceIdentity,
-  "ServiceManagedIdentity",
-  "java"
+  "BillingBenefitsManagedServiceIdentity",
+  "csharp"
 );
 @@clientName(
   Microsoft.BillingBenefits.ManagedServiceIdentityType,
-  "ServiceManagedIdentityType",
-  "java"
+  "BillingBenefitsManagedServiceIdentityType",
+  "csharp"
+);
+@@clientName(
+  ReservationOrderAliasResponse,
+  "BillingBenefitsReservationOrderAlias",
+  "csharp"
+);
+@@clientName(
+  AppliedScopeProperties,
+  "BillingBenefitsAppliedScopeProperties",
+  "csharp"
+);
+@@clientName(AppliedScopeType, "BillingBenefitsAppliedScopeType", "csharp");
+@@clientName(BillingPlan, "BillingBenefitsBillingPlan", "csharp");
+@@clientName(ProvisioningState, "BillingBenefitsProvisioningState", "csharp");
+@@clientName(
+  InstanceFlexibility,
+  "BillingBenefitsInstanceFlexibility",
+  "csharp"
+);
+@@clientName(
+  ReservedResourceType,
+  "BillingBenefitsReservedResourceType",
+  "csharp"
+);
+@@clientName(Term, "BillingBenefitsTerm", "csharp");
+@@clientName(SavingsPlanModel, "BillingBenefitsSavingsPlan", "csharp");
+@@clientName(Commitment, "BillingBenefitsCommitment", "csharp");
+@@clientName(CommitmentGrain, "BillingBenefitsCommitmentGrain", "csharp");
+@@clientName(ExtendedStatusInfo, "BillingBenefitsExtendedStatusInfo", "csharp");
+@@clientName(Utilization, "BillingBenefitsSavingsPlanUtilization", "csharp");
+@@clientName(
+  UtilizationAggregates,
+  "BillingBenefitsSavingsPlanUtilizationAggregate",
+  "csharp"
+);
+@@clientName(PurchaseRequest, "BillingBenefitsPurchaseContent", "csharp");
+@@clientName(
+  SavingsPlanValidResponseProperty,
+  "SavingsPlanValidateResult",
+  "csharp"
+);
+@@clientName(
+  SavingsPlanOrderAliasModel,
+  "BillingBenefitsSavingsPlanOrderAlias",
+  "csharp"
+);
+@@clientName(
+  SavingsPlanOrderModel,
+  "BillingBenefitsSavingsPlanOrder",
+  "csharp"
+);
+@@clientName(
+  RoleAssignmentEntity,
+  "BillingBenefitsRoleAssignmentEntity",
+  "csharp"
+);
+@@clientName(Price, "BillingBenefitsPrice", "csharp");
+@@clientName(PaymentDetail, "SavingsPlanOrderPaymentDetail", "csharp");
+@@clientName(PaymentStatus, "BillingBenefitsPaymentStatus", "csharp");
+@@clientName(
+  SavingsPlanUpdateValidateRequest,
+  "SavingsPlanUpdateValidateContent",
+  "csharp"
+);
+@@clientName(
+  SavingsPlanPurchaseValidateRequest,
+  "SavingsPlanPurchaseValidateContent",
+  "csharp"
+);
+@@clientName(
+  ReservationOrderAliasRequest,
+  "ReservationOrderAliasContent",
+  "csharp"
+);
+@@clientName(
+  SavingsPlanUpdateRequestProperties,
+  "BillingBenefitsSavingsPlanPatchProperties",
+  "csharp"
+);
+@@clientName(
+  ReservationOrderAliasResponseProperties.renew,
+  "IsRenewed",
+  "csharp"
+);
+@@clientName(
+  ReservationOrderAliasRequestProperties.renew,
+  "IsRenewed",
+  "csharp"
+);
+@@clientName(
+  SavingsPlanModelProperties.effectiveDateTime,
+  "EffectOn",
+  "csharp"
+);
+@@clientName(SavingsPlanModelProperties.expiryDateTime, "ExpireOn", "csharp");
+@@clientName(SavingsPlanModelProperties.renew, "IsRenewed", "csharp");
+@@clientName(PurchaseRequestProperties.effectiveDateTime, "EffectOn", "csharp");
+@@clientName(PurchaseRequestProperties.renew, "IsRenewed", "csharp");
+@@clientName(SavingsPlanValidResponseProperty.valid, "IsValid", "csharp");
+@@clientName(
+  SavingsPlanOrderModelProperties.expiryDateTime,
+  "ExpireOn",
+  "csharp"
+);
+@@clientName(PaymentDetail.paymentDate, "PayOn", "csharp");
+@@clientName(SavingsPlanUpdateRequestProperties.renew, "IsRenewed", "csharp");
+@@clientName(SavingsPlanOrderAliasProperties.renew, "IsRenewed", "csharp");
+@@clientName(BenefitValidateResponseProperty.valid, "IsValid", "csharp");
+@@clientName(
+  SellerResourceListRequestProperties.contributors,
+  "IncludeContributors",
+  "csharp"
+);
+@@clientName(
+  SellerResourceListRequestProperties.milestones,
+  "IncludeMilestones",
+  "csharp"
+);
+@@clientName(
+  MaccModelProperties.allowContributors,
+  "IsAllowContributors",
+  "csharp"
+);
+@@clientName(
+  MaccPatchRequestProperties.allowContributors,
+  "IsAllowContributors",
+  "csharp"
+);
+@@clientName(DiscountProperties, "BillingBenefitsDiscountProperties", "csharp");
+@@clientName(
+  ConditionalCreditProperties,
+  "BillingBenefitsConditionalCreditProperties",
+  "csharp"
+);
+@@alternateType(
+  ReservationOrderAliasResponseProperties.billingScopeId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  ReservationOrderAliasResponseProperties.reservationOrderId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  ReservationOrderAliasRequestProperties.billingScopeId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  AppliedScopeProperties.managementGroupId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  AppliedScopeProperties.subscriptionId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  AppliedScopeProperties.resourceGroupId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  SavingsPlanModelProperties.billingAccountId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  SavingsPlanModelProperties.billingProfileId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  SavingsPlanModelProperties.billingScopeId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  PurchaseRequestProperties.billingScopeId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  SavingsPlanOrderModelProperties.billingAccountId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  SavingsPlanOrderModelProperties.billingProfileId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  RoleAssignmentEntity.id,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  RoleAssignmentEntityProperties.roleDefinitionId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  RoleAssignmentEntityProperties.scope,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
 );
 
-// python
+@@clientName(ReservedResourceType.CosmosDb, "CosmosDB", "csharp");
+@@clientName(ReservedResourceType.MariaDb, "MariaDB", "csharp");
+@@clientName(ReservedResourceType.AVS, "Avs", "csharp");
 @@clientName(
-  Microsoft.BillingBenefits.ManagedServiceIdentity,
-  "ServiceManagedIdentity",
-  "python"
+  ReservationOrderAliasRequest,
+  "BillingBenefitsReservationOrderAliasCreateOrUpdateContent",
+  "csharp"
 );
 @@clientName(
-  Microsoft.BillingBenefits.ManagedServiceIdentityType,
-  "ServiceManagedIdentityType",
-  "python"
+  SavingsPlanOperationGroup.listAll,
+  "GetBillingBenefitsSavingsPlans",
+  "csharp"
+);
+@@alternateType(
+  ReservationOrderAliasResponse.location,
+  Azure.Core.azureLocation,
+  "csharp"
+);
+@@alternateType(
+  SavingsPlanOrderAliasProperties.billingScopeId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  SavingsPlanOrderAliasProperties.savingsPlanOrderId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(
+  SavingsPlanOrderModelProperties.billingScopeId,
+  Azure.Core.armResourceIdentifier,
+  "csharp"
+);
+
+@@usage(SavingsPlanModelProperties, Usage.input | Usage.output, "csharp");
+@@usage(SavingsPlanModel, Usage.input | Usage.output, "csharp");
+@@usage(ReservationOrderAliasRequest, Usage.input | Usage.output, "csharp");
+@@usage(
+  ReservationOrderAliasRequestProperties,
+  Usage.input | Usage.output,
+  "csharp"
 );
-@@clientName(Microsoft.BillingBenefits, "BillingBenefitsRP", "python");
-@@clientName(Microsoft.BillingBenefits.Term.P1Y, "P1_Y", "python");
-@@clientName(Microsoft.BillingBenefits.Term.P3Y, "P3_Y", "python");
-@@clientName(Microsoft.BillingBenefits.Term.P5Y, "P5_Y", "python");
-@@clientName(Microsoft.BillingBenefits.BillingPlan.P1M, "P1_M", "python");
+@@usage(PaymentDetail, Usage.input | Usage.output, "csharp");
+@@usage(BillingPlanInformation, Usage.input | Usage.output, "csharp");
+@@usage(ReservationOrderAliasResponse, Usage.input | Usage.output, "csharp");
+@@usage(SavingsPlanOrderModel, Usage.input | Usage.output, "csharp");
+
+@@alternateType(AppliedScopeProperties.tenantId, Azure.Core.uuid, "csharp");
+@@alternateType(
+  ReservationOrderAliasRequest.location,
+  Azure.Core.azureLocation,
+  "csharp"
+);
+
+// python: client name mitigation
+@@clientName(Microsoft.BillingBenefits, "BillingBenefitsMgmtClient", "python");
+
+// python: enum value naming mitigations
+@@clientName(BillingPlan.P1M, "P1_M", "python");
+@@clientName(Term.P1Y, "P1_Y", "python");
+@@clientName(Term.P3Y, "P3_Y", "python");
+@@clientName(Term.P5Y, "P5_Y", "python");
+
+@@clientName(
+  DiscountsOperationGroup.scopeList,
+  "listDiscountByScope",
+  "csharp"
+);
+@@clientName(
+  ConditionalCreditsOperationGroup.scopeList,
+  "listConditionalCreditByScope",
+  "csharp"
+);
+
+// csharp: preserve original public property name after flatten/lift-to-nullable generator fix
+@@clientName(MaccModelProperties.entityType, "MaccEntityType", "csharp");
+@@clientName(DiscountType, "DiscountTypeEnum", "go");