diff --git a/CHANGELOG.md b/CHANGELOG.md
index ba72fd2..3024348 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2.0.0] - 2026-07-17
+
+### Changed
+
+- Change `FacturapiException.getErrorCode()` to return strings, including converted legacy numeric codes.
+
 ## [1.3.0] - 2026-06-07
 
 ### Added
diff --git a/pom.xml b/pom.xml
index 4235f4a..a69187f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
 
   <groupId>io.facturapi</groupId>
   <artifactId>facturapi-java</artifactId>
-  <version>1.3.0</version>
+  <version>2.0.0</version>
   <name>facturapi-java</name>
   <description>Official Java SDK for Facturapi</description>
   <url>https://github.com/facturapi/facturapi-java</url>
diff --git a/src/main/java/io/facturapi/FacturapiException.java b/src/main/java/io/facturapi/FacturapiException.java
index 0e0839c..482baed 100644
--- a/src/main/java/io/facturapi/FacturapiException.java
+++ b/src/main/java/io/facturapi/FacturapiException.java
@@ -7,7 +7,7 @@
 
 public class FacturapiException extends RuntimeException {
   private final int statusCode;
-  private final Object errorCode;
+  private final String errorCode;
   private final String errorPath;
   private final String errorLocation;
   private final JsonNode errors;
@@ -29,14 +29,14 @@ public FacturapiException(String message, Throwable cause) {
     this.headers = Collections.emptyMap();
   }
 
-  public FacturapiException(String message, int statusCode, Object errorCode, String errorPath) {
+  public FacturapiException(String message, int statusCode, String errorCode, String errorPath) {
     this(message, statusCode, errorCode, errorPath, null, null, null, Collections.emptyMap());
   }
 
   public FacturapiException(
     String message,
     int statusCode,
-    Object errorCode,
+    String errorCode,
     String errorPath,
     String errorLocation,
     JsonNode errors,
@@ -57,7 +57,7 @@ public int getStatusCode() {
     return statusCode;
   }
 
-  public Object getErrorCode() {
+  public String getErrorCode() {
     return errorCode;
   }
 
diff --git a/src/main/java/io/facturapi/http/FacturapiHttpClient.java b/src/main/java/io/facturapi/http/FacturapiHttpClient.java
index 0fee0d7..a25c3b4 100644
--- a/src/main/java/io/facturapi/http/FacturapiHttpClient.java
+++ b/src/main/java/io/facturapi/http/FacturapiHttpClient.java
@@ -210,7 +210,7 @@ private static JsonNode firstDefined(JsonNode node, String... keys) {
   private FacturapiException buildApiException(String bodyText, Response response) {
     int statusCode = response.code();
     int resolvedStatus = statusCode;
-    Object errorCode = null;
+    String errorCode = null;
     String errorPath = null;
     String errorLocation = null;
     JsonNode errors = null;
@@ -245,18 +245,8 @@ private FacturapiException buildApiException(String bodyText, Response response)
           }
 
           JsonNode codeNode = firstDefined(root, "code");
-          if (codeNode != null && !codeNode.isNull()) {
-            if (codeNode.isTextual()) {
-              errorCode = codeNode.asText();
-            } else if (codeNode.isIntegralNumber()) {
-              errorCode = codeNode.intValue();
-            } else if (codeNode.isNumber()) {
-              errorCode = codeNode.numberValue();
-            } else if (codeNode.isBoolean()) {
-              errorCode = codeNode.asBoolean();
-            } else {
-              errorCode = codeNode.toString();
-            }
+          if (codeNode != null && (codeNode.isTextual() || codeNode.isNumber())) {
+            errorCode = codeNode.asText();
           }
 
           JsonNode pathNode = firstDefined(root, "path");
diff --git a/src/main/java/io/facturapi/models/InvoiceItem.java b/src/main/java/io/facturapi/models/InvoiceItem.java
index adcb675..dd35db8 100644
--- a/src/main/java/io/facturapi/models/InvoiceItem.java
+++ b/src/main/java/io/facturapi/models/InvoiceItem.java
@@ -14,7 +14,8 @@ public class InvoiceItem {
   private InvoiceItemThirdParty thirdParty;
   private String complement;
   private List<InvoiceItemPart> parts = new ArrayList<>();
-  private String propertyTaxAccount;
+  @JsonProperty("property_tax_account")
+  private List<String> propertyTaxAccounts = new ArrayList<>();
 
   public Double getQuantity() { return quantity; }
   public void setQuantity(Double quantity) { this.quantity = quantity; }
@@ -30,6 +31,8 @@ public class InvoiceItem {
   public void setComplement(String complement) { this.complement = complement; }
   public List<InvoiceItemPart> getParts() { return parts; }
   public void setParts(List<InvoiceItemPart> parts) { this.parts = parts; }
-  public String getPropertyTaxAccount() { return propertyTaxAccount; }
-  public void setPropertyTaxAccount(String propertyTaxAccount) { this.propertyTaxAccount = propertyTaxAccount; }
+  @JsonProperty("property_tax_account")
+  public List<String> getPropertyTaxAccounts() { return propertyTaxAccounts; }
+  @JsonProperty("property_tax_account")
+  public void setPropertyTaxAccounts(List<String> propertyTaxAccounts) { this.propertyTaxAccounts = propertyTaxAccounts; }
 }
diff --git a/src/test/java/io/facturapi/FacturapiHttpClientTest.java b/src/test/java/io/facturapi/FacturapiHttpClientTest.java
index 4917970..e8d6eac 100644
--- a/src/test/java/io/facturapi/FacturapiHttpClientTest.java
+++ b/src/test/java/io/facturapi/FacturapiHttpClientTest.java
@@ -77,4 +77,23 @@ void throwsFacturapiExceptionWithApiMessage() {
     assertEquals("3", ex.getHeaders().get("Retry-After").get(0));
     assertEquals("log_123", ex.getHeaders().get("x-facturapi-log-id").get(0));
   }
+
+  @Test
+  void convertsNumericApiErrorCodesToStrings() {
+    StubHttpClient httpClient = new StubHttpClient();
+    httpClient.enqueueJson(400, "{\"message\":\"Invalid customer\",\"code\":400}");
+
+    FacturapiHttpClient client = new FacturapiHttpClient(
+      FacturapiConfig.builder("sk_test_123")
+        .httpClient(httpClient.client())
+        .build()
+    );
+
+    FacturapiException ex = assertThrows(
+      FacturapiException.class,
+      () -> client.get("/customers/cus_1", null, GenericResponse.class)
+    );
+
+    assertEquals("400", ex.getErrorCode());
+  }
 }
diff --git a/src/test/java/io/facturapi/FacturapiResourcesTest.java b/src/test/java/io/facturapi/FacturapiResourcesTest.java
index b523184..18ae467 100644
--- a/src/test/java/io/facturapi/FacturapiResourcesTest.java
+++ b/src/test/java/io/facturapi/FacturapiResourcesTest.java
@@ -16,10 +16,12 @@
 import io.facturapi.enums.Taxability;
 import io.facturapi.http.FacturapiConfig;
 import io.facturapi.models.Customer;
+import io.facturapi.models.InvoiceItem;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 import java.time.Instant;
 import java.time.LocalDate;
+import java.util.List;
 import java.util.Map;
 import org.junit.jupiter.api.Test;
 
@@ -320,4 +322,18 @@ void objectMapperDeserializesCodeEnums() throws Exception {
     assertEquals(TaxType.IEPS, tax.getType());
     assertEquals(TaxFactor.EXENTO, tax.getFactor());
   }
+
+  @Test
+  void objectMapperDeserializesPropertyTaxAccountsAsArrays() throws Exception {
+    var mapper = FacturapiConfig.builder("sk_test").build().getObjectMapper();
+
+    var empty = mapper.readValue("{\"property_tax_account\":[]}", InvoiceItem.class);
+    var accounts = mapper.readValue(
+      "{\"property_tax_account\":[\"0102030405\"]}",
+      InvoiceItem.class
+    );
+
+    assertEquals(List.of(), empty.getPropertyTaxAccounts());
+    assertEquals(List.of("0102030405"), accounts.getPropertyTaxAccounts());
+  }
 }