diff --git a/domain/marketplace/__init__.py b/domain/marketplace/__init__.py
index d382887..0eaf436 100644
--- a/domain/marketplace/__init__.py
+++ b/domain/marketplace/__init__.py
@@ -1,7 +1,11 @@
 from .classified_ad import ClassifiedAd as ClassifiedAd
 from .classified_ad_id import ClassifiedAdId as ClassifiedAdId
+from .classified_ad_state import ClassifiedAdState as ClassifiedAdState
 from .classified_ad_text import ClassifiedAdText as ClassifiedAdText
 from .classified_ad_title import ClassifiedAdTitle as ClassifiedAdTitle
+from .invalid_entity_state_exception import (
+    InvalidEntityStateException as InvalidEntityStateException,
+)
 from .money import Money as Money
 from .price import Price as Price
 from .user_id import UserId as UserId
diff --git a/domain/marketplace/classified_ad.py b/domain/marketplace/classified_ad.py
index f914e79..f21a966 100644
--- a/domain/marketplace/classified_ad.py
+++ b/domain/marketplace/classified_ad.py
@@ -2,8 +2,12 @@ from dataclasses import dataclass, field
 from decimal import Decimal
 
 from domain.marketplace.classified_ad_id import ClassifiedAdId
+from domain.marketplace.classified_ad_state import ClassifiedAdState
 from domain.marketplace.classified_ad_text import ClassifiedAdText
 from domain.marketplace.classified_ad_title import ClassifiedAdTitle
+from domain.marketplace.invalid_entity_state_exception import (
+    InvalidEntityStateException,
+)
 from domain.marketplace.price import Price
 from domain.marketplace.user_id import UserId
 
@@ -15,3 +19,27 @@ class ClassifiedAd:
     title: ClassifiedAdTitle
     text: ClassifiedAdText
     price: Price = field(default_factory=lambda: Price(amount=Decimal("0.00")))
+    state: ClassifiedAdState | None = None
+
+    def request_to_publish(self):
+        errors = []
+        if not self.title.title:
+            errors.append("title")
+        if not self.text.text:
+            errors.append("text")
+        if self.price.amount <= 0:
+            errors.append("price")
+
+        if errors:
+            raise InvalidEntityStateException(
+                f"Cannot publish classified ad with missing or invalid: {', '.join(errors)}"
+            )
+
+        return ClassifiedAd(
+            id=self.id,
+            _ownerId=self._ownerId,
+            title=self.title,
+            text=self.text,
+            price=self.price,
+            state=ClassifiedAdState.PendingReview,
+        )
diff --git a/domain/marketplace/classified_ad_state.py b/domain/marketplace/classified_ad_state.py
new file mode 100644
index 0000000..f81309a
--- /dev/null
+++ b/domain/marketplace/classified_ad_state.py
@@ -0,0 +1,8 @@
+from enum import Enum
+
+
+class ClassifiedAdState(Enum):
+    PendingReview = "PendingReview"
+    Active = "Active"
+    Inactive = "Inactive"
+    MarkedAsSold = "MarkedAsSold"
diff --git a/domain/marketplace/invalid_entity_state_exception.py b/domain/marketplace/invalid_entity_state_exception.py
new file mode 100644
index 0000000..6289932
--- /dev/null
+++ b/domain/marketplace/invalid_entity_state_exception.py
@@ -0,0 +1,2 @@
+class InvalidEntityStateException(Exception):
+    pass
diff --git a/tests/test_classified_ad.py b/tests/test_classified_ad.py
index 17fc3e6..c96644f 100644
--- a/tests/test_classified_ad.py
+++ b/tests/test_classified_ad.py
@@ -5,8 +5,12 @@ import pytest
 
 from domain.marketplace.classified_ad import ClassifiedAd
 from domain.marketplace.classified_ad_id import ClassifiedAdId
+from domain.marketplace.classified_ad_state import ClassifiedAdState
 from domain.marketplace.classified_ad_text import ClassifiedAdText
 from domain.marketplace.classified_ad_title import ClassifiedAdTitle
+from domain.marketplace.invalid_entity_state_exception import (
+    InvalidEntityStateException,
+)
 from domain.marketplace.price import Price
 from domain.marketplace.user_id import UserId
 
@@ -127,3 +131,91 @@ def test_classified_ad_title_validation():
             text=ClassifiedAdText(text="Text"),
             price=Price(amount=Decimal("10.00")),
         )
+
+
+def test_request_to_publish_sets_state_to_pending_review():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title="Title"),
+        text=ClassifiedAdText(text="Text"),
+        price=Price(amount=Decimal("10.00")),
+    )
+
+    published = ad.request_to_publish()
+
+    assert published.state == ClassifiedAdState.PendingReview
+
+
+def test_request_to_publish_fails_when_title_empty():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title=""),
+        text=ClassifiedAdText(text="Text"),
+        price=Price(amount=Decimal("10.00")),
+    )
+
+    with pytest.raises(InvalidEntityStateException) as exc_info:
+        ad.request_to_publish()
+
+    assert "title" in str(exc_info.value)
+
+
+def test_request_to_publish_fails_when_text_empty():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title="Title"),
+        text=ClassifiedAdText(text=""),
+        price=Price(amount=Decimal("10.00")),
+    )
+
+    with pytest.raises(InvalidEntityStateException) as exc_info:
+        ad.request_to_publish()
+
+    assert "text" in str(exc_info.value)
+
+
+def test_request_to_publish_fails_when_price_is_zero():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title="Title"),
+        text=ClassifiedAdText(text="Text"),
+    )
+
+    with pytest.raises(InvalidEntityStateException) as exc_info:
+        ad.request_to_publish()
+
+    assert "price" in str(exc_info.value)
+
+
+def test_request_to_publish_reports_all_errors():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title=""),
+        text=ClassifiedAdText(text=""),
+    )
+
+    with pytest.raises(InvalidEntityStateException) as exc_info:
+        ad.request_to_publish()
+
+    assert "title" in str(exc_info.value)
+    assert "text" in str(exc_info.value)
+    assert "price" in str(exc_info.value)
+
+
+def test_request_to_publish_does_not_mutate_original():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title="Title"),
+        text=ClassifiedAdText(text="Text"),
+        price=Price(amount=Decimal("10.00")),
+    )
+
+    ad.request_to_publish()
+
+    assert ad.state is None