diff --git a/CHANGELOG.md b/CHANGELOG.md
index ec34052..aa1cd0e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.50.0 - 2026-03-03
+
+### Enhancements
+- Added logic to set `code` when upgrading version 1 `ErrorMsg` to newer versions
+
 ## 0.49.0 - 2026-02-24
 
 ### Enhancements
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2c37458..38f9f83 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,7 +6,7 @@ cmake_minimum_required(VERSION 3.24..4.2)
 
 project(
   databento
-  VERSION 0.49.0
+  VERSION 0.50.0
   LANGUAGES CXX
   DESCRIPTION "Official Databento client library"
 )
diff --git a/pkg/PKGBUILD b/pkg/PKGBUILD
index e21489e..7e9f33b 100644
--- a/pkg/PKGBUILD
+++ b/pkg/PKGBUILD
@@ -1,7 +1,7 @@
 # Maintainer: Databento <support@databento.com>
 _pkgname=databento-cpp
 pkgname=databento-cpp-git
-pkgver=0.49.0
+pkgver=0.50.0
 pkgrel=1
 pkgdesc="Official C++ client for Databento"
 arch=('any')
diff --git a/src/v1.cpp b/src/v1.cpp
index 2fdc57a..93460e0 100644
--- a/src/v1.cpp
+++ b/src/v1.cpp
@@ -211,6 +211,27 @@ v2::ErrorMsg ErrorMsg::ToV2() const {
       ErrorCode::Unset,
       std::numeric_limits<std::uint8_t>::max()};
   std::copy(err.begin(), err.end(), ret.err.begin());
+  const auto null_it = std::find(err.begin(), err.end(), '\0');
+  if (null_it != err.end()) {
+    constexpr auto kApiKeyDeactivated = "User or API key deactivated";
+    constexpr auto kConnectionLimit = "User has reached their open connection limit";
+    constexpr auto kSymbolResolution = "Failed to resolve symbol";
+    constexpr auto kInternalError = "Internal error";
+    constexpr auto kSlowClient = "Slow client detected for ";
+
+    if (std::strcmp(Err(), kApiKeyDeactivated) == 0) {
+      ret.code = ErrorCode::ApiKeyDeactivated;
+    } else if (std::strcmp(Err(), kConnectionLimit) == 0) {
+      ret.code = ErrorCode::ConnectionLimitExceeded;
+    } else if (std::strncmp(Err(), kSymbolResolution, std::strlen(kSymbolResolution)) ==
+               0) {
+      ret.code = ErrorCode::SymbolResolutionFailed;
+    } else if (std::strcmp(Err(), kInternalError) == 0) {
+      ret.code = ErrorCode::InternalError;
+    } else if (std::strncmp(Err(), kSlowClient, std::strlen(kSlowClient)) == 0) {
+      ret.code = ErrorCode::SkippedRecordsAfterSlowReading;
+    }
+  }
   return ret;
 }
 
diff --git a/tests/src/v1_tests.cpp b/tests/src/v1_tests.cpp
index 8063e39..6f4d757 100644
--- a/tests/src/v1_tests.cpp
+++ b/tests/src/v1_tests.cpp
@@ -39,4 +39,32 @@ TEST(V1Tests, TestSystemMsgCodeUpgrade) {
   const auto res5 = target.ToV2();
   EXPECT_EQ(res5.code, SystemCode::ReplayCompleted);
 }
+
+TEST(V1Tests, TestErrorMsgCodeUpgrade) {
+  v1::ErrorMsg target{RecordHeader{
+      sizeof(v1::ErrorMsg) / RecordHeader::kLengthMultiplier, RType::Error, 0, 0, {}}};
+  std::strcpy(target.err.data(), "User or API key deactivated");
+  const auto res1 = target.ToV2();
+  EXPECT_EQ(res1.code, ErrorCode::ApiKeyDeactivated);
+
+  target.err = {};
+  std::strcpy(target.err.data(), "User has reached their open connection limit");
+  const auto res2 = target.ToV2();
+  EXPECT_EQ(res2.code, ErrorCode::ConnectionLimitExceeded);
+
+  target.err = {};
+  std::strcpy(target.err.data(), "Failed to resolve symbol: AAPL");
+  const auto res3 = target.ToV2();
+  EXPECT_EQ(res3.code, ErrorCode::SymbolResolutionFailed);
+
+  target.err = {};
+  std::strcpy(target.err.data(), "Internal error");
+  const auto res4 = target.ToV2();
+  EXPECT_EQ(res4.code, ErrorCode::InternalError);
+
+  target.err = {};
+  std::strcpy(target.err.data(), "Slow client detected for mbo. Skipped records");
+  const auto res5 = target.ToV2();
+  EXPECT_EQ(res5.code, ErrorCode::SkippedRecordsAfterSlowReading);
+}
 }  // namespace databento::v1::tests