diff --git a/common/proto/accounting.proto b/common/proto/accounting.proto
index c6af402a..be33939a 100644
--- a/common/proto/accounting.proto
+++ b/common/proto/accounting.proto
@@ -433,6 +433,25 @@ message OpeningBalanceAccountMapping {
   string created_by_user_id = 14;
 }
 
+// A predecessor account still holding value that no mapping carries into the
+// target period. Closing the target period drops these balances silently, so
+// each one is either an account left to map or one deliberately closed out.
+message UnmappedSourceAccount {
+  int64 source_period_id = 1;
+  string source_profile_name = 2;
+  repeated string source_account_segments = 3;
+  string currency = 4;
+  // Signed balance uses the debit-positive convention, and is never zero.
+  string closing_balance = 5;
+  OpeningBalanceStatus status = 6;
+}
+
 message ListOpeningBalanceAccountsResponse {
   repeated OpeningBalanceAccountMapping mappings = 1;
+
+  // Empty while the target period still inherits every predecessor balance by
+  // account path. Populated once the period carries balances by explicit
+  // mapping only, which happens when the predecessor belongs to another
+  // profile or when the period has at least one mapping of its own.
+  repeated UnmappedSourceAccount unmapped_source_accounts = 2;
 }
diff --git a/common/src/proto/descriptor.bin b/common/src/proto/descriptor.bin
index d894e81f..e9e23e75 100644
Binary files a/common/src/proto/descriptor.bin and b/common/src/proto/descriptor.bin differ
diff --git a/common/src/proto/komp_ac.accounting.rs b/common/src/proto/komp_ac.accounting.rs
index d722ecac..65a336ea 100644
--- a/common/src/proto/komp_ac.accounting.rs
+++ b/common/src/proto/komp_ac.accounting.rs
@@ -476,10 +476,37 @@ pub struct OpeningBalanceAccountMapping {
     #[prost(string, tag = "14")]
     pub created_by_user_id: ::prost::alloc::string::String,
 }
+/// A predecessor account still holding value that no mapping carries into the
+/// target period. Closing the target period drops these balances silently, so
+/// each one is either an account left to map or one deliberately closed out.
+#[derive(Clone, PartialEq, Eq, Hash, ::prost::Message)]
+pub struct UnmappedSourceAccount {
+    #[prost(int64, tag = "1")]
+    pub source_period_id: i64,
+    #[prost(string, tag = "2")]
+    pub source_profile_name: ::prost::alloc::string::String,
+    #[prost(string, repeated, tag = "3")]
+    pub source_account_segments: ::prost::alloc::vec::Vec<
+        ::prost::alloc::string::String,
+    >,
+    #[prost(string, tag = "4")]
+    pub currency: ::prost::alloc::string::String,
+    /// Signed balance uses the debit-positive convention, and is never zero.
+    #[prost(string, tag = "5")]
+    pub closing_balance: ::prost::alloc::string::String,
+    #[prost(enumeration = "OpeningBalanceStatus", tag = "6")]
+    pub status: i32,
+}
 #[derive(Clone, PartialEq, ::prost::Message)]
 pub struct ListOpeningBalanceAccountsResponse {
     #[prost(message, repeated, tag = "1")]
     pub mappings: ::prost::alloc::vec::Vec<OpeningBalanceAccountMapping>,
+    /// Empty while the target period still inherits every predecessor balance by
+    /// account path. Populated once the period carries balances by explicit
+    /// mapping only, which happens when the predecessor belongs to another
+    /// profile or when the period has at least one mapping of its own.
+    #[prost(message, repeated, tag = "2")]
+    pub unmapped_source_accounts: ::prost::alloc::vec::Vec<UnmappedSourceAccount>,
 }
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, ::prost::Enumeration)]
 #[repr(i32)]
diff --git a/server b/server
index 82402387..45e95554 160000
--- a/server
+++ b/server
@@ -1 +1 @@
-Subproject commit 8240238732b5487ca9d5ccaad32e3789805a7638
+Subproject commit 45e95554c9a9ba82d6b421bf5599e2a74f966a3e