diff --git a/src/main/java/com/checkout/accounts/ArticlesOfAssociation.java b/src/main/java/com/checkout/accounts/ArticlesOfAssociation.java
new file mode 100644
index 00000000..0b136f40
--- /dev/null
+++ b/src/main/java/com/checkout/accounts/ArticlesOfAssociation.java
@@ -0,0 +1,33 @@
+package com.checkout.accounts;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * Memorandum or articles of association document, supplied when onboarding a sub-entity.
+ *
+ * <p>Required on the company full onboarding variants. The API expects an object carrying the
+ * document type and the uploaded file ID, which is why this class exists: the field on
+ * {@link OnboardSubEntityDocuments} used to be the {@link ArticlesOfAssociationType} enum, so
+ * the SDK serialized a bare string and the API rejected the request.</p>
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class ArticlesOfAssociation {
+
+    /**
+     * The type of document being used as the memorandum or articles of association.
+     */
+    private ArticlesOfAssociationType type;
+
+    /**
+     * The ID of the front side of the document as represented within Checkout.com systems,
+     * as returned when the file was uploaded.
+     */
+    private String front;
+
+}
diff --git a/src/main/java/com/checkout/accounts/OnboardSubEntityDocuments.java b/src/main/java/com/checkout/accounts/OnboardSubEntityDocuments.java
index 40f2fb3a..1784e352 100644
--- a/src/main/java/com/checkout/accounts/OnboardSubEntityDocuments.java
+++ b/src/main/java/com/checkout/accounts/OnboardSubEntityDocuments.java
@@ -16,7 +16,7 @@ public final class OnboardSubEntityDocuments {
 
     private CompanyVerification companyVerification;
 
-    private ArticlesOfAssociationType articlesOfAssociation;
+    private ArticlesOfAssociation articlesOfAssociation;
 
     private BankVerification bankVerification;
 
diff --git a/src/test/java/com/checkout/accounts/OnboardSubEntityDocumentsSerializationTest.java b/src/test/java/com/checkout/accounts/OnboardSubEntityDocumentsSerializationTest.java
new file mode 100644
index 00000000..b2182d88
--- /dev/null
+++ b/src/test/java/com/checkout/accounts/OnboardSubEntityDocumentsSerializationTest.java
@@ -0,0 +1,85 @@
+package com.checkout.accounts;
+
+import com.checkout.GsonSerializer;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Covers the onboarding documents that carry a type plus a file ID.
+ *
+ * <p>articlesOfAssociation was typed as the ArticlesOfAssociationType enum and there was no
+ * ArticlesOfAssociation class, so the SDK serialized {@code "articles_of_association":
+ * "articles_of_association"} where the API requires an object. That document, which is required
+ * on the company full variants, could not be sent from Java at all.</p>
+ */
+class OnboardSubEntityDocumentsSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeArticlesOfAssociationAsAnObject() {
+        final OnboardSubEntityDocuments documents = OnboardSubEntityDocuments.builder()
+                .articlesOfAssociation(ArticlesOfAssociation.builder()
+                        .type(ArticlesOfAssociationType.ARTICLES_OF_ASSOCIATION)
+                        .front("file_6lbss42ezvoufcb2beo76rvwly")
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(documents);
+
+        assertTrue(json.contains("\"articles_of_association\":{"), json);
+        assertTrue(json.contains("\"type\":\"articles_of_association\""), json);
+        assertTrue(json.contains("\"front\":\"file_6lbss42ezvoufcb2beo76rvwly\""), json);
+        // The old shape. If this ever comes back, the API rejects the request.
+        assertFalse(json.contains("\"articles_of_association\":\"articles_of_association\""), json);
+    }
+
+    @Test
+    void shouldSerializeMemorandumOfAssociation() {
+        final OnboardSubEntityDocuments documents = OnboardSubEntityDocuments.builder()
+                .articlesOfAssociation(ArticlesOfAssociation.builder()
+                        .type(ArticlesOfAssociationType.MEMORANDUM_OF_ASSOCIATION)
+                        .front("file_6lbss42ezvoufcb2beo76rvwly")
+                        .build())
+                .build();
+
+        assertTrue(serializer.toJson(documents).contains("\"type\":\"memorandum_of_association\""));
+    }
+
+    /**
+     * The sibling documents were already objects. Asserted here so the three stay consistent:
+     * they are the same shape in the API and a future edit should not split them apart again.
+     */
+    @Test
+    void shouldSerializeBankVerificationAndShareholderStructureAsObjects() {
+        final OnboardSubEntityDocuments documents = OnboardSubEntityDocuments.builder()
+                .bankVerification(BankVerification.builder()
+                        .type(BankVerificationType.BANK_STATEMENT)
+                        .front("file_bank")
+                        .build())
+                .shareholderStructure(ShareholderStructure.builder()
+                        .type(ShareholderStructureType.CERTIFIED_SHAREHOLDER_STRUCTURE)
+                        .front("file_shareholder")
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(documents);
+
+        assertTrue(json.contains("\"bank_verification\":{\"type\":\"bank_statement\""), json);
+        assertTrue(json.contains("\"shareholder_structure\":{\"type\":\"certified_shareholder_structure\""), json);
+    }
+
+    @Test
+    void shouldDeserializeArticlesOfAssociation() {
+        final String json = "{\"articles_of_association\":{\"type\":\"articles_of_association\","
+                + "\"front\":\"file_6lbss42ezvoufcb2beo76rvwly\"}}";
+
+        final OnboardSubEntityDocuments documents = serializer.fromJson(json, OnboardSubEntityDocuments.class);
+
+        assertEquals(ArticlesOfAssociationType.ARTICLES_OF_ASSOCIATION, documents.getArticlesOfAssociation().getType());
+        assertEquals("file_6lbss42ezvoufcb2beo76rvwly", documents.getArticlesOfAssociation().getFront());
+    }
+}