diff --git a/stripe/src/main/java/com/stripe/android/model/Source.kt b/stripe/src/main/java/com/stripe/android/model/Source.kt
index 12ee813029a..178f8ae1d6b 100644
--- a/stripe/src/main/java/com/stripe/android/model/Source.kt
+++ b/stripe/src/main/java/com/stripe/android/model/Source.kt
@@ -2,6 +2,7 @@ package com.stripe.android.model
 
 import androidx.annotation.Size
 import androidx.annotation.StringDef
+import com.stripe.android.model.Source.SourceFlow
 import com.stripe.android.model.Source.SourceType
 import com.stripe.android.model.StripeJsonUtils.optLong
 import com.stripe.android.model.StripeJsonUtils.optString
@@ -13,28 +14,89 @@ import org.json.JSONObject
  *
  * See [Sources API Reference](https://stripe.com/docs/api/sources/object).
  */
-data class Source private constructor(
+data class Source internal constructor(
+    /**
+     * Unique identifier for the object.
+     */
     override val id: String?,
-    val amount: Long?,
-    val clientSecret: String?,
-    val codeVerification: SourceCodeVerification?,
-    val created: Long?,
-    val currency: String?,
 
+    /**
+     * A positive integer in the smallest currency unit (that is, 100 cents for $1.00, or 1 for ¥1,
+     * Japanese Yen being a zero-decimal currency) representing the total amount associated with
+     * the source. This is the amount for which the source will be chargeable once ready.
+     * Required for `single_use` sources.
+     */
+    val amount: Long? = null,
+
+    /**
+     * The client secret of the source. Used for client-side retrieval using a publishable key.
+     */
+    val clientSecret: String? = null,
+
+    /**
+     * Information related to the code verification flow. Present if the source is authenticated
+     * by a verification code (`flow` is `code_verification`).
+     */
+    val codeVerification: SourceCodeVerification? = null,
+
+    /**
+     * Time at which the object was created. Measured in seconds since the Unix epoch.
+     */
+    val created: Long? = null,
+
+    /**
+     * Three-letter [ISO code for the currency](https://stripe.com/docs/currencies) associated with
+     * the source. This is the currency for which the source will be chargeable once ready.
+     * Required for `single_use` sources.
+     */
+    val currency: String? = null,
+
+    /**
+     * The authentication `flow` of the source.
+     * `flow` is one of `redirect`, `receiver`, `code_verification`, `none`.
+     */
     @param:SourceFlow @field:SourceFlow @get:SourceFlow
     val flow: String? = null,
 
-    val isLiveMode: Boolean?,
-    val metaData: Map<String, String>?,
-    val owner: SourceOwner?,
+    /**
+     * Has the value true if the object exists in live mode or the value false if the object
+     * exists in test mode.
+     */
+    val isLiveMode: Boolean? = null,
+
+    /**
+     * Set of key-value pairs that you can attach to an object. This can be useful for storing
+     * additional information about the object in a structured format.
+     */
+    val metaData: Map<String, String>? = null,
+
+    /**
+     * Information about the owner of the payment instrument that may be used or required by
+     * particular source types.
+     */
+    val owner: SourceOwner? = null,
+
+    /**
+     * Information related to the receiver flow.
+     * Present if the source is a receiver ([flow] is [SourceFlow.RECEIVER]).
+     */
     val receiver: SourceReceiver? = null,
+
+    /**
+     * Information related to the redirect flow. Present if the source is authenticated by a
+     * redirect ([flow] is [SourceFlow.REDIRECT]).
+     */
     val redirect: SourceRedirect? = null,
 
+    /**
+     * The status of the source, one of `canceled`, `chargeable`, `consumed`, `failed`,
+     * or `pending`. Only `chargeable` sources can be used to create a charge.
+     */
     @param:SourceStatus @field:SourceStatus @get:SourceStatus
-    val status: String?,
+    val status: String? = null,
 
-    val sourceTypeData: Map<String, Any?>?,
-    val sourceTypeModel: StripeSourceTypeModel?,
+    val sourceTypeData: Map<String, Any?>? = null,
+    val sourceTypeModel: StripeSourceTypeModel? = null,
 
     /**
      * Gets the [SourceType] of this Source, as one of the enumerated values.
@@ -55,10 +117,21 @@ data class Source private constructor(
      */
     val typeRaw: String,
 
+    /**
+     * Either `reusable` or `single_use`. Whether this source should be reusable or not. Some source
+     * types may or may not be reusable by construction, while others may leave the option at
+     * creation. If an incompatible value is passed, an error will be returned.
+     */
     @param:Usage @field:Usage @get:Usage
-    val usage: String?,
+    val usage: String? = null,
+
+    private val weChatParam: WeChat? = null,
 
-    private val weChatParam: WeChat?
+    /**
+     * Information about the items and shipping associated with the source. Required for
+     * transactional credit (for example Klarna) sources before you can charge it.
+     */
+    val sourceOrder: SourceOrder? = null
 ) : StripeModel(), StripePaymentSource {
 
     val weChat: WeChat
@@ -149,6 +222,7 @@ data class Source private constructor(
         private const val FIELD_OWNER: String = "owner"
         private const val FIELD_RECEIVER: String = "receiver"
         private const val FIELD_REDIRECT: String = "redirect"
+        private const val FIELD_SOURCE_ORDER: String = "source_order"
         private const val FIELD_STATUS: String = "status"
         private const val FIELD_TYPE: String = "type"
         private const val FIELD_USAGE: String = "usage"
@@ -181,11 +255,10 @@ data class Source private constructor(
             val sourceTypeModel = SourceCardData.fromJson(jsonObject)
 
             return Source(
-                id, null, null, null,
-                null, null, null, null,
-                null, null, null, null,
-                null, null, sourceTypeModel, SourceType.CARD,
-                SourceType.CARD, null, null
+                id,
+                sourceTypeModel = sourceTypeModel,
+                type = SourceType.CARD,
+                typeRaw = SourceType.CARD
             )
         }
 
@@ -240,6 +313,9 @@ data class Source private constructor(
                     WeChat.fromJson(jsonObject.optJSONObject(FIELD_WECHAT) ?: JSONObject())
                 } else {
                     null
+                },
+                sourceOrder = jsonObject.optJSONObject(FIELD_SOURCE_ORDER)?.let {
+                    SourceOrder.fromJson(it)
                 }
             )
         }
diff --git a/stripe/src/test/java/com/stripe/android/model/SourceFixtures.kt b/stripe/src/test/java/com/stripe/android/model/SourceFixtures.kt
index 09becf251de..8450d2c2dbd 100644
--- a/stripe/src/test/java/com/stripe/android/model/SourceFixtures.kt
+++ b/stripe/src/test/java/com/stripe/android/model/SourceFixtures.kt
@@ -1,10 +1,10 @@
 package com.stripe.android.model
 
+import com.stripe.android.model.SourceOrderFixtures.SOURCE_ORDER_JSON
 import org.json.JSONObject
 
 internal object SourceFixtures {
 
-    @JvmField
     val ALIPAY_JSON = JSONObject(
         """
         {
@@ -43,8 +43,7 @@ internal object SourceFixtures {
         """.trimIndent()
     )
 
-    @JvmField
-    val WECHAT = Source.fromJson(JSONObject(
+    val WECHAT = requireNotNull(Source.fromJson(JSONObject(
         """
         {
             "id": "src_1F4ZSkBNJ02",
@@ -84,10 +83,9 @@ internal object SourceFixtures {
             }
         }
         """.trimIndent()
-    ))!!
+    )))
 
-    @JvmField
-    val SOURCE_CARD = Source.fromJson(JSONObject(
+    val SOURCE_CARD = requireNotNull(Source.fromJson(JSONObject(
         """
         {
             "id": "src_19t3xKBZqEXluyI4uz2dxAfQ",
@@ -132,10 +130,9 @@ internal object SourceFixtures {
             }
         }
         """.trimIndent()
-    ))!!
+    )))
 
-    @JvmField
-    val CARD = Source.fromJson(JSONObject(
+    val CARD = requireNotNull(Source.fromJson(JSONObject(
         """
         {
             "id": "card_1ELxrOCRMbs6FrXfdxOGjnaD",
@@ -162,9 +159,8 @@ internal object SourceFixtures {
             "tokenization_method": null
         }
         """.trimIndent()
-    ))!!
+    )))
 
-    @JvmField
     val APPLE_PAY = JSONObject(
         """
         {
@@ -194,8 +190,7 @@ internal object SourceFixtures {
         """.trimIndent()
     )
 
-    @JvmField
-    val SOURCE_REDIRECT_JSON = JSONObject(
+    private val SOURCE_REDIRECT_JSON = JSONObject(
         """
         {
             "return_url": "https://google.com",
@@ -205,11 +200,11 @@ internal object SourceFixtures {
         """.trimIndent()
     )
 
-    @JvmField
-    val SOURCE_REDIRECT = SourceRedirect.fromJson(SOURCE_REDIRECT_JSON)!!
+    val SOURCE_REDIRECT = requireNotNull(
+        SourceRedirect.fromJson(SOURCE_REDIRECT_JSON)
+    )
 
-    @JvmField
-    val SOURCE_CODE_VERIFICATION_JSON = JSONObject(
+    private val SOURCE_CODE_VERIFICATION_JSON = JSONObject(
         """
         {
             "attempts_remaining": 3,
@@ -218,13 +213,11 @@ internal object SourceFixtures {
         """.trimIndent()
     )
 
-    @JvmField
-    val SOURCE_CODE_VERIFICATION = SourceCodeVerification.fromJson(
-        SOURCE_CODE_VERIFICATION_JSON
-    )!!
+    val SOURCE_CODE_VERIFICATION = requireNotNull(
+        SourceCodeVerification.fromJson(SOURCE_CODE_VERIFICATION_JSON)
+    )
 
-    @JvmField
-    val SOURCE_RECEIVER_JSON = JSONObject(
+    private val SOURCE_RECEIVER_JSON = JSONObject(
         """
         {
             "address": "test_1MBhWS3uv4ynCfQXF3xQjJkzFPukr4K56N",
@@ -235,10 +228,8 @@ internal object SourceFixtures {
         """.trimIndent()
     )
 
-    @JvmField
-    val SOURCE_RECEIVER = SourceReceiver.fromJson(SOURCE_RECEIVER_JSON)!!
+    val SOURCE_RECEIVER = requireNotNull(SourceReceiver.fromJson(SOURCE_RECEIVER_JSON))
 
-    @JvmField
     val SOURCE_OWNER_WITH_NULLS = JSONObject(
         """
         {
@@ -254,7 +245,6 @@ internal object SourceFixtures {
         """.trimIndent()
     )
 
-    @JvmField
     val SOURCE_OWNER_WITHOUT_NULLS = JSONObject(
         """
         {
@@ -284,7 +274,6 @@ internal object SourceFixtures {
         """.trimIndent()
     )
 
-    @JvmField
     internal val SOURCE_CARD_DATA_WITH_APPLE_PAY_JSON = JSONObject(
         """
             {
@@ -303,4 +292,24 @@ internal object SourceFixtures {
             }
             """.trimIndent()
     )
+
+    internal val SOURCE_WITH_SOURCE_ORDER = requireNotNull(Source.fromJson(JSONObject(
+        """
+        {
+            "id": "src_1FfB6GKmrohBAXC",
+            "object": "source",
+            "amount": 1000,
+            "created": 1573848540,
+            "currency": "eur",
+            "flow": "redirect",
+            "livemode": false,
+            "metadata": {},
+            "source_order": $SOURCE_ORDER_JSON,
+            "statement_descriptor": null,
+            "status": "pending",
+            "type": "klarna",
+            "usage": "single_use"
+        }
+        """.trimIndent()
+    )))
 }
diff --git a/stripe/src/main/java/com/stripe/android/model/SourceOrderFixtures.kt b/stripe/src/test/java/com/stripe/android/model/SourceOrderFixtures.kt
similarity index 55%
rename from stripe/src/main/java/com/stripe/android/model/SourceOrderFixtures.kt
rename to stripe/src/test/java/com/stripe/android/model/SourceOrderFixtures.kt
index dee85a8d49b..8443f662afc 100644
--- a/stripe/src/main/java/com/stripe/android/model/SourceOrderFixtures.kt
+++ b/stripe/src/test/java/com/stripe/android/model/SourceOrderFixtures.kt
@@ -4,7 +4,7 @@ import org.json.JSONObject
 
 internal object SourceOrderFixtures {
 
-    val SOURCE_ORDER = SourceOrder.fromJson(JSONObject(
+    val SOURCE_ORDER_JSON = JSONObject(
         """
         {
             "amount": 1000,
@@ -53,5 +53,46 @@ internal object SourceOrderFixtures {
             }
         }
         """.trimIndent()
-    ))
+    )
+
+    val SOURCE_ORDER = SourceOrder(
+        amount = 1000,
+        currency = "eur",
+        email = "jrosen@example.com",
+        items = listOf(
+            SourceOrder.Item(
+                type = SourceOrder.Item.Type.Sku,
+                amount = 1000,
+                currency = "eur",
+                description = "shoes",
+                quantity = 1
+            ),
+            SourceOrder.Item(
+                type = SourceOrder.Item.Type.Sku,
+                amount = 1000,
+                currency = "eur",
+                description = "socks",
+                quantity = 1
+            ),
+            SourceOrder.Item(
+                type = SourceOrder.Item.Type.Shipping,
+                amount = 499,
+                currency = "eur",
+                description = "ground shipping"
+            ),
+            SourceOrder.Item(
+                type = SourceOrder.Item.Type.Tax,
+                amount = 299,
+                currency = "eur",
+                description = "sales tax"
+            )
+        ),
+        shipping = SourceOrder.Shipping(
+            address = AddressFixtures.ADDRESS,
+            carrier = "UPS",
+            name = "Jenny Rosen",
+            phone = "1-800-555-1234",
+            trackingNumber = "tracking_12345"
+        )
+    )
 }
diff --git a/stripe/src/test/java/com/stripe/android/model/SourceOrderTest.kt b/stripe/src/test/java/com/stripe/android/model/SourceOrderTest.kt
index 57a1a915f27..f916d310e4e 100644
--- a/stripe/src/test/java/com/stripe/android/model/SourceOrderTest.kt
+++ b/stripe/src/test/java/com/stripe/android/model/SourceOrderTest.kt
@@ -7,46 +7,9 @@ class SourceOrderTest {
 
     @Test
     fun testParse() {
-        val expected = SourceOrder(
-            amount = 1000,
-            currency = "eur",
-            email = "jrosen@example.com",
-            items = listOf(
-                SourceOrder.Item(
-                    type = SourceOrder.Item.Type.Sku,
-                    amount = 1000,
-                    currency = "eur",
-                    description = "shoes",
-                    quantity = 1
-                ),
-                SourceOrder.Item(
-                    type = SourceOrder.Item.Type.Sku,
-                    amount = 1000,
-                    currency = "eur",
-                    description = "socks",
-                    quantity = 1
-                ),
-                SourceOrder.Item(
-                    type = SourceOrder.Item.Type.Shipping,
-                    amount = 499,
-                    currency = "eur",
-                    description = "ground shipping"
-                ),
-                SourceOrder.Item(
-                    type = SourceOrder.Item.Type.Tax,
-                    amount = 299,
-                    currency = "eur",
-                    description = "sales tax"
-                )
-            ),
-            shipping = SourceOrder.Shipping(
-                address = AddressFixtures.ADDRESS,
-                carrier = "UPS",
-                name = "Jenny Rosen",
-                phone = "1-800-555-1234",
-                trackingNumber = "tracking_12345"
-            )
+        assertEquals(
+            SourceOrderFixtures.SOURCE_ORDER,
+            SourceOrder.fromJson(SourceOrderFixtures.SOURCE_ORDER_JSON)
         )
-        assertEquals(expected, SourceOrderFixtures.SOURCE_ORDER)
     }
 }
diff --git a/stripe/src/test/java/com/stripe/android/model/SourceTest.kt b/stripe/src/test/java/com/stripe/android/model/SourceTest.kt
index 36220b70cd0..5b7ae103f5b 100644
--- a/stripe/src/test/java/com/stripe/android/model/SourceTest.kt
+++ b/stripe/src/test/java/com/stripe/android/model/SourceTest.kt
@@ -58,6 +58,14 @@ class SourceTest {
         assertEquals("wxa0df8has9d78ce", weChat.appId)
     }
 
+    @Test
+    fun fromJson_withSourceOrder() {
+        assertEquals(
+            SourceOrderFixtures.SOURCE_ORDER,
+            SourceFixtures.SOURCE_WITH_SOURCE_ORDER.sourceOrder
+        )
+    }
+
     internal companion object {
         internal val EXAMPLE_JSON_SOURCE_WITHOUT_NULLS = JSONObject(
             """