diff --git a/common/proto/ecb.proto b/common/proto/ecb.proto
index a6cb4984..b0b909d3 100644
--- a/common/proto/ecb.proto
+++ b/common/proto/ecb.proto
@@ -274,6 +274,11 @@ message EcbConversionEvidence {
   // already_same_currency, since none of those were priced by the policy's
   // source itself -- a human entered them.
   optional string observation_source_id = 29;
+
+  // Exact immutable profile policy version selected for this conversion's
+  // accounting date. Absent only when no conversion policy was needed because
+  // determination_method is already_same_currency.
+  optional int64 rate_source_policy_id = 30;
 }
 
 message ListEcbConversionEvidenceResponse {
diff --git a/common/src/proto/descriptor.bin b/common/src/proto/descriptor.bin
index 846dbfca..ae11d9a1 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.ecb.rs b/common/src/proto/komp_ac.ecb.rs
index 191e4b09..313dddc1 100644
--- a/common/src/proto/komp_ac.ecb.rs
+++ b/common/src/proto/komp_ac.ecb.rs
@@ -295,6 +295,11 @@ pub struct EcbConversionEvidence {
     /// source itself -- a human entered them.
     #[prost(string, optional, tag = "29")]
     pub observation_source_id: ::core::option::Option<::prost::alloc::string::String>,
+    /// Exact immutable profile policy version selected for this conversion's
+    /// accounting date. Absent only when no conversion policy was needed because
+    /// determination_method is already_same_currency.
+    #[prost(int64, optional, tag = "30")]
+    pub rate_source_policy_id: ::core::option::Option<i64>,
 }
 #[derive(Clone, PartialEq, ::prost::Message)]
 pub struct ListEcbConversionEvidenceResponse {
diff --git a/server b/server
index 81f04101..b864da0a 160000
--- a/server
+++ b/server
@@ -1 +1 @@
-Subproject commit 81f0410185afd59eb4f8a746dabdbacacd44146b
+Subproject commit b864da0a9b76062bb0f6236e9b6e3d0e82bc11fe