diff --git a/src/test/java/seedu/address/logic/parser/UnmarkCommandParserTest.java b/src/test/java/seedu/address/logic/parser/UnmarkCommandParserTest.java
new file mode 100644
index 00000000000..c5028a30931
--- /dev/null
+++ b/src/test/java/seedu/address/logic/parser/UnmarkCommandParserTest.java
@@ -0,0 +1,102 @@
+package seedu.address.logic.parser;
+
+import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
+import static seedu.address.logic.commands.CommandTestUtil.DATE_DESC_APPOINTMENT_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.END_TIME_DESC_APPOINTMENT_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.INVALID_DATE_DESC;
+import static seedu.address.logic.commands.CommandTestUtil.INVALID_END_TIME_DESC;
+import static seedu.address.logic.commands.CommandTestUtil.INVALID_NRIC_DESC;
+import static seedu.address.logic.commands.CommandTestUtil.INVALID_START_TIME_DESC;
+import static seedu.address.logic.commands.CommandTestUtil.NRIC_DESC_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.PREAMBLE_NON_EMPTY;
+import static seedu.address.logic.commands.CommandTestUtil.PREAMBLE_WHITESPACE;
+import static seedu.address.logic.commands.CommandTestUtil.START_TIME_DESC_APPOINTMENT_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_APPOINTMENT_DATE_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_APPOINTMENT_END_TIME_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_APPOINTMENT_START_TIME_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_NRIC_BOB;
+import static seedu.address.logic.parser.CommandParserTestUtil.assertParseFailure;
+import static seedu.address.logic.parser.CommandParserTestUtil.assertParseSuccess;
+import static seedu.address.testutil.TypicalAppointments.BOB_APPT;
+
+import org.junit.jupiter.api.Test;
+
+import seedu.address.commons.core.date.Date;
+import seedu.address.logic.commands.UnmarkCommand;
+import seedu.address.model.appointment.Appointment;
+import seedu.address.model.appointment.TimePeriod;
+import seedu.address.model.person.Nric;
+import seedu.address.testutil.AppointmentBuilder;
+
+public class UnmarkCommandParserTest {
+
+    private final UnmarkCommandParser parser = new UnmarkCommandParser();
+
+    @Test
+    public void parse_allFieldsPresent_success() {
+        Appointment expectedAppointment = new AppointmentBuilder(BOB_APPT).build();
+
+        // whitespace only preamble
+        assertParseSuccess(parser, PREAMBLE_WHITESPACE + NRIC_DESC_BOB + DATE_DESC_APPOINTMENT_BOB
+                        + START_TIME_DESC_APPOINTMENT_BOB + END_TIME_DESC_APPOINTMENT_BOB,
+                new UnmarkCommand(
+                        expectedAppointment.getNric(),
+                        expectedAppointment.getDate(),
+                        expectedAppointment.getTimePeriod()
+                ));
+    }
+
+    @Test
+    public void parse_compulsoryFieldMissing_failure() {
+        String expectedMessage = String.format(MESSAGE_INVALID_COMMAND_FORMAT, UnmarkCommand.MESSAGE_USAGE);
+
+        // missing NRIC prefix
+        assertParseFailure(parser, DATE_DESC_APPOINTMENT_BOB + START_TIME_DESC_APPOINTMENT_BOB
+                        + END_TIME_DESC_APPOINTMENT_BOB,
+                expectedMessage);
+
+        // missing date prefix
+        assertParseFailure(parser, NRIC_DESC_BOB + START_TIME_DESC_APPOINTMENT_BOB
+                        + END_TIME_DESC_APPOINTMENT_BOB,
+                expectedMessage);
+
+        // missing start time prefix
+        assertParseFailure(parser, NRIC_DESC_BOB + DATE_DESC_APPOINTMENT_BOB
+                        + END_TIME_DESC_APPOINTMENT_BOB,
+                expectedMessage);
+
+        // missing end time prefix
+        assertParseFailure(parser, NRIC_DESC_BOB + DATE_DESC_APPOINTMENT_BOB
+                        + START_TIME_DESC_APPOINTMENT_BOB,
+                expectedMessage);
+
+        // all prefixes missing
+        assertParseFailure(parser, VALID_NRIC_BOB + VALID_APPOINTMENT_DATE_BOB
+                        + VALID_APPOINTMENT_START_TIME_BOB + VALID_APPOINTMENT_END_TIME_BOB,
+                expectedMessage);
+    }
+
+    @Test
+    public void parse_invalidValue_failure() {
+        // invalid NRIC
+        assertParseFailure(parser, INVALID_NRIC_DESC + DATE_DESC_APPOINTMENT_BOB
+                + START_TIME_DESC_APPOINTMENT_BOB + END_TIME_DESC_APPOINTMENT_BOB, Nric.MESSAGE_CONSTRAINTS);
+
+        // invalid date
+        assertParseFailure(parser, NRIC_DESC_BOB + INVALID_DATE_DESC
+                + START_TIME_DESC_APPOINTMENT_BOB + END_TIME_DESC_APPOINTMENT_BOB, Date.MESSAGE_CONSTRAINTS);
+
+        // invalid time period
+        assertParseFailure(parser, NRIC_DESC_BOB + DATE_DESC_APPOINTMENT_BOB
+                + INVALID_START_TIME_DESC + INVALID_END_TIME_DESC, TimePeriod.MESSAGE_CONSTRAINTS);
+
+        // multiple invalid values, only the first one reported
+        assertParseFailure(parser, INVALID_NRIC_DESC + INVALID_DATE_DESC
+                + START_TIME_DESC_APPOINTMENT_BOB + END_TIME_DESC_APPOINTMENT_BOB, Nric.MESSAGE_CONSTRAINTS);
+
+        // non-empty preamble
+        assertParseFailure(parser, PREAMBLE_NON_EMPTY + NRIC_DESC_BOB + DATE_DESC_APPOINTMENT_BOB
+                        + START_TIME_DESC_APPOINTMENT_BOB + END_TIME_DESC_APPOINTMENT_BOB,
+                String.format(MESSAGE_INVALID_COMMAND_FORMAT, UnmarkCommand.MESSAGE_USAGE));
+    }
+}