diff --git a/components/brave_ads/core/internal/account/transactions/transaction_info.cc b/components/brave_ads/core/internal/account/transactions/transaction_info.cc
index 1f288b1c3a29..d0aa830867e8 100644
--- a/components/brave_ads/core/internal/account/transactions/transaction_info.cc
+++ b/components/brave_ads/core/internal/account/transactions/transaction_info.cc
@@ -41,9 +41,9 @@ bool TransactionInfo::operator!=(const TransactionInfo& other) const {
 }
 
 bool TransactionInfo::IsValid() const {
-  return !id.empty() && !creative_instance_id.empty() &&
-         ad_type != AdType::kUndefined &&
-         confirmation_type != ConfirmationType::kUndefined && created_at;
+  return !id.empty() && created_at && !creative_instance_id.empty() &&
+         !segment.empty() && ad_type != AdType::kUndefined &&
+         confirmation_type != ConfirmationType::kUndefined;
 }
 
 }  // namespace brave_ads
diff --git a/components/brave_ads/core/internal/account/transactions/transactions_database_table.cc b/components/brave_ads/core/internal/account/transactions/transactions_database_table.cc
index 4541fc73ca2c..a0f1ae9f1ebe 100644
--- a/components/brave_ads/core/internal/account/transactions/transactions_database_table.cc
+++ b/components/brave_ads/core/internal/account/transactions/transactions_database_table.cc
@@ -294,6 +294,63 @@ void MigrateToV39(mojom::DBTransactionInfo* const transaction) {
   transaction->commands.push_back(std::move(command));
 }
 
+void MigrateToV40(mojom::DBTransactionInfo* const transaction) {
+  CHECK(transaction);
+
+  {
+    // Delete legacy transactions with an undefined `creative_instance_id`,
+    // `segment` or `ad_type`.
+    mojom::DBCommandInfoPtr command = mojom::DBCommandInfo::New();
+    command->type = mojom::DBCommandInfo::Type::EXECUTE;
+    command->sql =
+        R"(
+          DELETE FROM
+            transactions
+          WHERE
+            COALESCE(creative_instance_id, '') = ''
+            OR COALESCE(segment, '') = ''
+            OR ad_type = '';)";
+    transaction->commands.push_back(std::move(command));
+  }
+
+  {
+    // Create a temporary table:
+    //   - with a new `creative_instance_id` column constraint.
+    //   - with a new `segment` column constraint.
+    //   - with a new `reconciled_at` default value.
+    mojom::DBCommandInfoPtr command = mojom::DBCommandInfo::New();
+    command->type = mojom::DBCommandInfo::Type::EXECUTE;
+    command->sql =
+        R"(
+          CREATE TABLE transactions_temp (
+            id TEXT NOT NULL PRIMARY KEY ON CONFLICT REPLACE,
+            created_at TIMESTAMP NOT NULL,
+            creative_instance_id TEXT NOT NULL,
+            value DOUBLE NOT NULL,
+            segment TEXT NOT NULL,
+            ad_type TEXT NOT NULL,
+            confirmation_type TEXT NOT NULL,
+            reconciled_at TIMESTAMP DEFAULT 0
+          );)";
+    transaction->commands.push_back(std::move(command));
+
+    // Copy legacy columns to the temporary table, drop the legacy table, rename
+    // the temporary table and create an index.
+    const std::vector<std::string> columns = {
+        "id",      "created_at", "creative_instance_id", "value",
+        "segment", "ad_type",    "confirmation_type",    "reconciled_at"};
+
+    CopyTableColumns(transaction, "transactions", "transactions_temp", columns,
+                     /*should_drop=*/true);
+
+    RenameTable(transaction, "transactions_temp", "transactions");
+  }
+
+  // Optimize database query for `GetForDateRange`.
+  CreateTableIndex(transaction, /*table_name=*/"transactions",
+                   /*columns=*/{"created_at"});
+}
+
 }  // namespace
 
 void Transactions::Save(const TransactionList& transactions,
@@ -427,12 +484,12 @@ void Transactions::Create(mojom::DBTransactionInfo* transaction) {
           CREATE TABLE transactions (
             id TEXT NOT NULL PRIMARY KEY ON CONFLICT REPLACE,
             created_at TIMESTAMP NOT NULL,
-            creative_instance_id TEXT,
+            creative_instance_id TEXT NOT NULL,
             value DOUBLE NOT NULL,
-            segment TEXT,
+            segment TEXT NOT NULL,
             ad_type TEXT NOT NULL,
             confirmation_type TEXT NOT NULL,
-            reconciled_at TIMESTAMP
+            reconciled_at TIMESTAMP DEFAULT 0
           );)";
   transaction->commands.push_back(std::move(command));
 
@@ -474,6 +531,11 @@ void Transactions::Migrate(mojom::DBTransactionInfo* transaction,
       MigrateToV39(transaction);
       break;
     }
+
+    case 40: {
+      MigrateToV40(transaction);
+      break;
+    }
   }
 }
 
diff --git a/components/brave_ads/core/internal/legacy_migration/database/database_constants.h b/components/brave_ads/core/internal/legacy_migration/database/database_constants.h
index f81025912adc..7cf497cbf908 100644
--- a/components/brave_ads/core/internal/legacy_migration/database/database_constants.h
+++ b/components/brave_ads/core/internal/legacy_migration/database/database_constants.h
@@ -8,8 +8,8 @@
 
 namespace brave_ads::database {
 
-inline constexpr int kVersion = 39;
-inline constexpr int kCompatibleVersion = 39;
+inline constexpr int kVersion = 40;
+inline constexpr int kCompatibleVersion = 40;
 
 }  // namespace brave_ads::database
 
diff --git a/components/brave_ads/core/test/data/database/database_schema_40.sqlite b/components/brave_ads/core/test/data/database/database_schema_40.sqlite
new file mode 100644
index 000000000000..c4ac00450bbb
Binary files /dev/null and b/components/brave_ads/core/test/data/database/database_schema_40.sqlite differ
diff --git a/components/brave_ads/core/test/data/database/invalid_database_schema_40.sqlite b/components/brave_ads/core/test/data/database/invalid_database_schema_40.sqlite
new file mode 100644
index 000000000000..c69cbc01e628
Binary files /dev/null and b/components/brave_ads/core/test/data/database/invalid_database_schema_40.sqlite differ