diff --git a/Sources/ElixxirDAppsSDK/Models/SingleUseCallbackReport.swift b/Sources/ElixxirDAppsSDK/Models/SingleUseCallbackReport.swift
index a4acd5536503612e3260dc89e81088302e03d3da..032f7c1c2b75b5e527037569a6d9867cc2487633 100644
--- a/Sources/ElixxirDAppsSDK/Models/SingleUseCallbackReport.swift
+++ b/Sources/ElixxirDAppsSDK/Models/SingleUseCallbackReport.swift
@@ -5,33 +5,21 @@ public struct SingleUseCallbackReport: Equatable {
     rounds: [Int],
     payload: Data,
     partner: Data,
-    ephId: EphId
+    ephId: Int64,
+    receptionId: Data
   ) {
     self.rounds = rounds
     self.payload = payload
     self.partner = partner
     self.ephId = ephId
+    self.receptionId = receptionId
   }
 
   public var rounds: [Int]
   public var payload: Data
   public var partner: Data
-  public var ephId: EphId
-}
-
-extension SingleUseCallbackReport {
-  public struct EphId: Equatable {
-    public init(
-      ephId: [Int],
-      source: Data
-    ) {
-      self.ephId = ephId
-      self.source = source
-    }
-
-    public var ephId: [Int]
-    public var source: Data
-  }
+  public var ephId: Int64
+  public var receptionId: Data
 }
 
 extension SingleUseCallbackReport: Codable {
@@ -40,6 +28,7 @@ extension SingleUseCallbackReport: Codable {
     case payload = "Payload"
     case partner = "Partner"
     case ephId = "EphID"
+    case receptionId = "ReceptionID"
   }
 
   public static func decode(_ data: Data) throws -> Self {
@@ -50,10 +39,3 @@ extension SingleUseCallbackReport: Codable {
     try JSONEncoder().encode(self)
   }
 }
-
-extension SingleUseCallbackReport.EphId: Codable {
-  enum CodingKeys: String, CodingKey {
-    case ephId = "EphId"
-    case source = "Source"
-  }
-}
diff --git a/Tests/ElixxirDAppsSDKTests/Models/SingleUseCallbackReportTests.swift b/Tests/ElixxirDAppsSDKTests/Models/SingleUseCallbackReportTests.swift
index 0f478cb70b764e9ec733b0f4fd29cb114c540a3b..9ec6e42b82df25d53709f163762ee38b903db376 100644
--- a/Tests/ElixxirDAppsSDKTests/Models/SingleUseCallbackReportTests.swift
+++ b/Tests/ElixxirDAppsSDKTests/Models/SingleUseCallbackReportTests.swift
@@ -7,17 +7,15 @@ final class SingleUseCallbackReportTests: XCTestCase {
     let rounds: [Int] = [1, 5, 9]
     let payloadB64 = "rSuPD35ELWwm5KTR9ViKIz/r1YGRgXIl5792SF8o8piZzN6sT4Liq4rUU/nfOPvQEjbfWNh/NYxdJ72VctDnWw=="
     let partnerB64 = "emV6aW1hAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD"
-    let ephId: [Int] = [0, 0, 0, 0, 0, 0, 3, 89]
-    let ephIdSourceB64 = "emV6aW1hAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD"
+    let ephId: Int64 = 1_655_533
+    let receptionIdB64 = "emV6aW1hAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD"
     let jsonString = """
     {
       "Rounds": [\(rounds.map { "\($0)" }.joined(separator: ", "))],
       "Payload": "\(payloadB64)",
       "Partner": "\(partnerB64)",
-      "EphID": {
-        "EphId": [\(ephId.map { "\($0)" }.joined(separator: ", "))],
-        "Source": "\(ephIdSourceB64)"
-      }
+      "EphID": \(ephId),
+      "ReceptionID": "\(receptionIdB64)"
     }
     """
     let jsonData = jsonString.data(using: .utf8)!
@@ -27,10 +25,8 @@ final class SingleUseCallbackReportTests: XCTestCase {
       rounds: rounds,
       payload: Data(base64Encoded: payloadB64)!,
       partner: Data(base64Encoded: partnerB64)!,
-      ephId: .init(
-        ephId: ephId,
-        source: Data(base64Encoded: ephIdSourceB64)!
-      )
+      ephId: ephId,
+      receptionId: Data(base64Encoded: receptionIdB64)!
     ))
 
     let encodedModel = try model.encode()