diff --git a/server-rs/crates/api-server/src/runtime_profile.rs b/server-rs/crates/api-server/src/runtime_profile.rs
index 833f397c0..ee069594f 100644
--- a/server-rs/crates/api-server/src/runtime_profile.rs
+++ b/server-rs/crates/api-server/src/runtime_profile.rs
@@ -2656,6 +2656,11 @@ mod tests {
                 RuntimeProfileMembershipErrorCode::PlanCatalogMissing,
                 "会员目录缺少档位 pro",
             ),
+            // 目录价格 / 每期泥点倒挂属后端配置错误，与 UpgradeRejected 分开暴露机器码。
+            (
+                RuntimeProfileMembershipErrorCode::InvalidPlanConfig,
+                "会员升级被拒绝: catalog_pricing_inverted",
+            ),
         ] {
             let error = map_runtime_profile_client_error(SpacetimeClientError::ProcedureRejected {
                 code: code.into(),
diff --git a/server-rs/crates/module-runtime/src/domain.rs b/server-rs/crates/module-runtime/src/domain.rs
index 057336e08..1569ce7d2 100644
--- a/server-rs/crates/module-runtime/src/domain.rs
+++ b/server-rs/crates/module-runtime/src/domain.rs
@@ -1506,7 +1506,7 @@ pub enum RuntimeProfileMembershipErrorCode {
     ProductIdUnparseable,
     /// 会员商品已迁移到档位目录，旧商品不再可用。
     MembershipProductRetired,
-    /// 后台会员档位改价 / 改权益配置校验失败。
+    /// 后台会员档位改价 / 改权益配置校验失败，或读取目录时发现价格 / 每期泥点倒挂。
     InvalidPlanConfig,
 }
 
diff --git a/server-rs/crates/module-runtime/src/lib.rs b/server-rs/crates/module-runtime/src/lib.rs
index 116e51d10..a38eb90b7 100644
--- a/server-rs/crates/module-runtime/src/lib.rs
+++ b/server-rs/crates/module-runtime/src/lib.rs
@@ -27,12 +27,13 @@ pub use llm_billing::*;
 pub use membership::{
     MEMBERSHIP_UNLIMITED_CONCURRENCY, PROFILE_MEMBERSHIP_RECOMMENDED_PLAN,
     RuntimeProfileMembershipPlanRecord, RuntimeProfileMembershipPlanSnapshot,
-    RuntimeProfileMembershipUpgradeQuoteInput, beijing_local_micros,
-    build_runtime_profile_membership_plan_snapshot, check_expired_membership_upgrade_settlement,
-    is_unlimited_concurrency, membership_cycle_window, membership_expires_at,
-    parse_runtime_profile_membership_product_id, quote_runtime_profile_membership_upgrade,
-    resolve_runtime_profile_membership_plan_row, runtime_profile_membership_plan_catalog,
-    runtime_profile_membership_plan_rank, runtime_profile_membership_product_id,
+    RuntimeProfileMembershipUpgradeQuoteInput, RuntimeProfileMembershipUpgradeRejection,
+    beijing_local_micros, build_runtime_profile_membership_plan_snapshot,
+    check_expired_membership_upgrade_settlement, is_unlimited_concurrency, membership_cycle_window,
+    membership_expires_at, parse_runtime_profile_membership_product_id,
+    quote_runtime_profile_membership_upgrade, resolve_runtime_profile_membership_plan_row,
+    runtime_profile_membership_plan_catalog, runtime_profile_membership_plan_rank,
+    runtime_profile_membership_product_id,
     validate_runtime_profile_membership_plan_row_against_catalog,
 };
 
diff --git a/server-rs/crates/module-runtime/src/membership/upgrade.rs b/server-rs/crates/module-runtime/src/membership/upgrade.rs
index 3a6786325..e2677ec35 100644
--- a/server-rs/crates/module-runtime/src/membership/upgrade.rs
+++ b/server-rs/crates/module-runtime/src/membership/upgrade.rs
@@ -77,6 +77,11 @@ pub enum RuntimeProfileMembershipUpgradeRejection {
     TargetPlanNotPurchasable,
     /// 报价入参的数值不变量被破坏（期号越界、账期窗口非法或 `now` 不在窗口内）：拒绝，而不是静默夹取。
     InvalidQuoteInput,
+    /// 目录价格 / 每期泥点未随 rank 严格递增（相等或倒挂）。
+    ///
+    /// 与 [`Self::InvalidQuoteInput`] 分开：这是后端目录配置错误，不是调用方入参错误，
+    /// 对外应映射为配置类错误码（`invalid_plan_config`），便于监控区分。
+    CatalogPricingInverted,
     /// 补差价订单结算时会员已到期，且订单金额不够覆盖整期新购价：应重新下单购买。
     MembershipExpiredBeforeSettlement,
 }
@@ -89,9 +94,21 @@ impl RuntimeProfileMembershipUpgradeRejection {
             Self::NotUpgrade => "not_upgrade",
             Self::TargetPlanNotPurchasable => "target_plan_not_purchasable",
             Self::InvalidQuoteInput => "invalid_quote_input",
+            Self::CatalogPricingInverted => "catalog_pricing_inverted",
             Self::MembershipExpiredBeforeSettlement => "membership_expired_before_settlement",
         }
     }
+
+    /// 对外 procedure 错误码：目录价格 / 每期泥点倒挂属后端配置错误，与调用方入参错误分开，
+    /// 便于按机器码定位；其余拒绝仍统一为 `UpgradeRejected`。
+    pub fn error_code(&self) -> crate::RuntimeProfileMembershipErrorCode {
+        match self {
+            Self::CatalogPricingInverted => {
+                crate::RuntimeProfileMembershipErrorCode::InvalidPlanConfig
+            }
+            _ => crate::RuntimeProfileMembershipErrorCode::UpgradeRejected,
+        }
+    }
 }
 
 /// 本期剩余比例（ppm）：`剩余微秒 / 本期实际微秒`，向下取整，已过期或时长非法时为 0。
@@ -184,8 +201,9 @@ pub fn quote_runtime_profile_membership_upgrade(
 
     // 目录价格 / 每期泥点必须严格随 rank 递增；相等或倒挂都直接拒绝，
     // 否则 checked_sub 会把「相等」算成 0 元升级 / 0 补点，违背目录不变量。
+    // 这是后端目录配置错误，用独立变体与调用方入参错误区分。
     if target.price_cents <= current.price_cents || target.period_points <= current.period_points {
-        return Err(RuntimeProfileMembershipUpgradeRejection::InvalidQuoteInput);
+        return Err(RuntimeProfileMembershipUpgradeRejection::CatalogPricingInverted);
     }
     let price_delta_cents = target.price_cents - current.price_cents;
     let points_delta = target.period_points - current.period_points;
@@ -247,6 +265,7 @@ fn ceil_div(numerator: u128, denominator: u128) -> u64 {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::RuntimeProfileMembershipErrorCode;
     use crate::RuntimeProfileMembershipPlan;
     use crate::membership::catalog::resolve_runtime_profile_membership_plan_snapshot;
     use crate::membership::cycle::beijing_local_micros;
@@ -485,7 +504,7 @@ mod tests {
                 target: target.clone(),
                 ..base_input()
             }),
-            Err(RuntimeProfileMembershipUpgradeRejection::InvalidQuoteInput)
+            Err(RuntimeProfileMembershipUpgradeRejection::CatalogPricingInverted)
         );
 
         target.price_cents = current.price_cents + 1;
@@ -496,7 +515,7 @@ mod tests {
                 target: target.clone(),
                 ..base_input()
             }),
-            Err(RuntimeProfileMembershipUpgradeRejection::InvalidQuoteInput)
+            Err(RuntimeProfileMembershipUpgradeRejection::CatalogPricingInverted)
         );
 
         // 中文注释：相等同样破坏「严格随 rank 递增」，必须拒绝；旧实现用 checked_sub
@@ -509,7 +528,17 @@ mod tests {
                 target,
                 ..base_input()
             }),
-            Err(RuntimeProfileMembershipUpgradeRejection::InvalidQuoteInput)
+            Err(RuntimeProfileMembershipUpgradeRejection::CatalogPricingInverted)
+        );
+
+        // 中文注释：目录倒挂对外映射为配置错误码，与调用方入参错误（UpgradeRejected）区分。
+        assert_eq!(
+            RuntimeProfileMembershipUpgradeRejection::CatalogPricingInverted.error_code(),
+            RuntimeProfileMembershipErrorCode::InvalidPlanConfig
+        );
+        assert_eq!(
+            RuntimeProfileMembershipUpgradeRejection::InvalidQuoteInput.error_code(),
+            RuntimeProfileMembershipErrorCode::UpgradeRejected
         );
     }
 
diff --git a/server-rs/crates/spacetime-module/src/runtime/active/profile.rs b/server-rs/crates/spacetime-module/src/runtime/active/profile.rs
index 18ad8f4ed..0bffc6c79 100644
--- a/server-rs/crates/spacetime-module/src/runtime/active/profile.rs
+++ b/server-rs/crates/spacetime-module/src/runtime/active/profile.rs
@@ -8764,12 +8764,7 @@ fn build_profile_membership_upgrade_quote_record(
         &target,
         ctx.timestamp,
     ))
-    .map_err(|rejection| {
-        RuntimeProfileMembershipDomainError::new(
-            RuntimeProfileMembershipErrorCode::UpgradeRejected,
-            format!("会员升级被拒绝: {}", rejection.as_str()),
-        )
-    })?;
+    .map_err(membership_upgrade_rejection_error)?;
 
     Ok(RuntimeProfileMembershipUpgradeQuoteSnapshot {
         current_plan: current.plan,
@@ -8786,6 +8781,19 @@ fn build_profile_membership_upgrade_quote_record(
     })
 }
 
+/// 会员升级拒绝 → procedure 错误码。
+///
+/// 目录价格 / 每期泥点倒挂是后端配置错误，映射为 `InvalidPlanConfig`，与客户端入参错误
+/// （`UpgradeRejected`）区分开，便于按错误码定位；人读文案仍带具体 rejection 原因。
+fn membership_upgrade_rejection_error(
+    rejection: RuntimeProfileMembershipUpgradeRejection,
+) -> RuntimeProfileMembershipDomainError {
+    RuntimeProfileMembershipDomainError::new(
+        rejection.error_code(),
+        format!("会员升级被拒绝: {}", rejection.as_str()),
+    )
+}
+
 /// 后台改价 / 改权益。`rank` 与 `plan` 不可改：`plan` 是主键（即身份），`rank` 是升级比较基准。
 fn upsert_profile_membership_plan_record(
     ctx: &ReducerContext,
@@ -10107,12 +10115,7 @@ fn build_profile_membership_order_snapshot(
     let quote = quote_runtime_profile_membership_upgrade(membership_upgrade_quote_input(
         &row, &current, &target, created_at,
     ))
-    .map_err(|rejection| {
-        RuntimeProfileMembershipDomainError::new(
-            RuntimeProfileMembershipErrorCode::UpgradeRejected,
-            format!("会员升级被拒绝: {}", rejection.as_str()),
-        )
-    })?;
+    .map_err(membership_upgrade_rejection_error)?;
     Ok(ProfileMembershipOrderSnapshot {
         change_kind: RuntimeProfileMembershipChangeKind::Upgrade,
         plan,
@@ -10731,12 +10734,7 @@ fn build_recomputed_profile_membership_settlement(
         &target,
         purchased_at,
     ))
-    .map_err(|rejection| {
-        RuntimeProfileMembershipDomainError::new(
-            RuntimeProfileMembershipErrorCode::UpgradeRejected,
-            format!("会员升级被拒绝: {}", rejection.as_str()),
-        )
-    })?;
+    .map_err(membership_upgrade_rejection_error)?;
     Ok(ProfileMembershipSettlement {
         change_kind: RuntimeProfileMembershipChangeKind::Upgrade,
         plan,