diff --git a/app-common/src/main/java/im/angry/openeuicc/util/ActivationCode.kt b/app-common/src/main/java/im/angry/openeuicc/util/ActivationCode.kt
index 3aca0d6..c34da4c 100644
--- a/app-common/src/main/java/im/angry/openeuicc/util/ActivationCode.kt
+++ b/app-common/src/main/java/im/angry/openeuicc/util/ActivationCode.kt
@@ -9,15 +9,27 @@ data class ActivationCode(
     companion object {
         fun fromString(input: String): ActivationCode {
             val components = input.removePrefix("LPA:").split('$')
-            if (components.size < 2 || components[0] != "1") {
+                .map { it.trim().ifEmpty { null } }
+            if (components.size < 2 || components[0] != "1" || components[1].isNullOrEmpty()) {
                 throw IllegalArgumentException("Invalid activation code format")
             }
             return ActivationCode(
-                address = components[1].trim(),
-                matchingId = components.getOrNull(2)?.trim()?.ifBlank { null },
-                oid = components.getOrNull(3)?.trim()?.ifBlank { null },
-                confirmationCodeRequired = components.getOrNull(4)?.trim() == "1"
+                components[1]!!,
+                components.getOrNull(2),
+                components.getOrNull(3),
+                components.getOrNull(4) == "1"
             )
         }
     }
+
+    override fun toString(): String {
+        val parts = buildList {
+            add("1")
+            add(address)
+            add(matchingId ?: "")
+            add(oid ?: "")
+            add(if (confirmationCodeRequired) "1" else "")
+        }
+        return parts.joinToString("$").trimEnd('$')
+    }
 }
\ No newline at end of file
diff --git a/app-common/src/test/java/im/angry/openeuicc/util/ActivationCodeTest.kt b/app-common/src/test/java/im/angry/openeuicc/util/ActivationCodeTest.kt
new file mode 100644
index 0000000..aadaab3
--- /dev/null
+++ b/app-common/src/test/java/im/angry/openeuicc/util/ActivationCodeTest.kt
@@ -0,0 +1,71 @@
+package im.angry.openeuicc.util
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertThrows
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class ActivationCodeTest {
+    /**
+     * @see {https://www.gsma.com/esim/wp-content/uploads/2020/06/SGP.22-v2.2.2.pdf#page=112}
+     */
+    @Suppress("SpellCheckingInspection")
+    private val expectedFixtures = mapOf(
+        // if SM-DP+ OID and Confirmation Code Required Flag are not present
+        Pair(
+            "1\$SMDP.GSMA.COM\$04386-AGYFT-A74Y8-3F815",
+            ActivationCode("SMDP.GSMA.COM", "04386-AGYFT-A74Y8-3F815", null, false)
+        ),
+        // if SM-DP+ OID is not present and Confirmation Code Required Flag is present
+        Pair(
+            "1\$SMDP.GSMA.COM\$04386-AGYFT-A74Y8-3F815\$\$1",
+            ActivationCode("SMDP.GSMA.COM", "04386-AGYFT-A74Y8-3F815", null, true)
+        ),
+        // if SM-DP+ OID and Confirmation Code Required flag are present
+        Pair(
+            "1\$SMDP.GSMA.COM\$04386-AGYFT-A74Y8-3F815\$1.3.6.1.4.1.31746\$1",
+            ActivationCode("SMDP.GSMA.COM", "04386-AGYFT-A74Y8-3F815", "1.3.6.1.4.1.31746", true)
+        ),
+        // if SM-DP+ OID is present and Confirmation Code Required Flag is not present
+        Pair(
+            "1\$SMDP.GSMA.COM\$04386-AGYFT-A74Y8-3F815\$1.3.6.1.4.1.31746",
+            ActivationCode("SMDP.GSMA.COM", "04386-AGYFT-A74Y8-3F815", "1.3.6.1.4.1.31746", false)
+        ),
+        // if SM-DP+ OID is present, Activation token is left blank and Confirmation Code Required Flag is not present
+        Pair(
+            "1\$SMDP.GSMA.COM\$\$1.3.6.1.4.1.31746",
+            ActivationCode("SMDP.GSMA.COM", null, "1.3.6.1.4.1.31746", false)
+        ),
+    )
+
+    @Suppress("SpellCheckingInspection")
+    private val unexpectedFixtures = listOf(
+        "", "LPA:",
+        "1", "LPA:1",
+        "1$", "LPA:1$",
+        "1$$", "LPA:1$$",
+        "2\$SMDP.GSMA.COM", "LPA:2\$SMDP.GSMA.COM",
+    )
+
+    @Test
+    fun testParsing() {
+        for ((input, expected) in expectedFixtures) {
+            val actual = ActivationCode.fromString(input)
+            assertEquals(expected.address, actual.address)
+            assertEquals(expected.matchingId, actual.matchingId)
+            assertEquals(expected.oid, actual.oid)
+            assertEquals(expected.confirmationCodeRequired, actual.confirmationCodeRequired)
+            assertEquals(input, expected.toString())
+            assertTrue(expected == actual)
+        }
+    }
+
+    @Test
+    fun testUnexpected() {
+        for (fixture in unexpectedFixtures) {
+            assertThrows(IllegalArgumentException::class.java) {
+                ActivationCode.fromString(fixture)
+            }
+        }
+    }
+}
\ No newline at end of file