Vienna Convention on the Law of Treaties

SECTION 2. RESERVATIONS

Article 19
Formulation of reservations

A State may, when signing, ratifying, accepting, approving or acceding to a
treaty, formulate a reservation unless:

(a) the reservation is prohibited by the treaty;
(b) the treaty provides that only specified reservations, which do not
include the reservation in question, may be made; or
(c) in cases not falling under sub-paragraphs (a) and (b), the
reservation is incompatible with the object and purpose of the
treaty.

Article 20
Acceptance of and objection to reservations

1. A reservation expressly authorized by a treaty does not require any
subsequent acceptance by the other contracting States unless the treaty so
provides.

2. When it appears from the limited number of the negotiating States and
the object and purpose of a treaty that the application of the treaty in
its entirety between all the parties is an essential condition of the
consent of each one to be bound by the treaty, a reservation requires
acceptance by all the parties.

3. When a treaty is a constituent instrument of an international
organization and unless it otherwise provides, a reservation requires the
acceptance of the competent organ of that organization.

4. In cases not falling under the preceding paragraphs and unless the
treaty otherwise provides:

(a) acceptance by another contracting State of a reservation constitutes
the reserving State a party to the treaty in relation to that other
State if or when the treaty is in force for those States;
(b) an objection by another contracting State to a reservation does not
preclude the entry into force of the treaty as between the objecting
and reserving States unless a contrary intention is definitely
expressed by the objecting State;
(c) an act expressing a State’s consent to be bound by the treaty and
containing a reservation is effective as soon as at least one other
contracting State has accepted the reservation.

5. For the purposes of paragraphs 2 and 4 and unless the treaty otherwise
provides, a reservation is considered to have been accepted by a State if
it shall have raised no objection to the reservation by the end of a period
of twelve months after it was notified of the reservation or by the date on
which it expressed its consent to be bound by the treaty, whichever is
later.

Article 21
Legal effects of reservations and of objections to reservations

1. A reservation established with regard to another party in accordance
with articles 19, 20 and 23:

(a) modifies for the reserving State in its relations with that other
party the provisions of the treaty to which the reservation relates
to the extent of the reservation; and
(b) modifies those provisions to the same extent for that other party in
its relations with the reserving State.

2. The reservation does not modify the provisions of the treaty for the
other parties to the treaty inter se.

3. When a State objecting to a reservation has not opposed the entry into
force of the treaty between itself and the reserving State, the provisions
to which the reservation relates do not apply as between the two States to
the extent of the reservation.

Article 22
Withdrawal of reservations and of objections to reservations

1. Unless the treaty otherwise provides, a reservation may be withdrawn at
any time and the consent of a State which has accepted the reservation is
not required for its withdrawal.

2. Unless the treaty otherwise provides, an objection to a reservation may
be withdrawn at any time.

3. Unless the treaty otherwise provides, or it is otherwise agreed:

(a) the withdrawal of a reservation becomes operative in relation to
another contracting State only when notice of it has been received by
that State;
(b) the withdrawal of an objection to a reservation becomes operative
only when notice of it has been received by the State which
formulated the reservation.

Article 23
Procedure regarding reservations

1. A reservation, an express acceptance of a reservation and an objection
to a reservation must be formulated in writing and communicated to the
contracting States and other States entitled to become parties to the
treaty.

2. If formulated when signing the treaty subject to ratification,
acceptance or approval, a reservation must be formally confirmed by the
reserving State when expressing its consent to be bound by the treaty. In
such a case the reservation shall be considered as having been made on the
date of its confirmation.

3. An express acceptance of, or an objection to, a reservation made
previously to confirmation of the reservation does not itself require
confirmation.

4. The withdrawal of a reservation or of an objection to a reservation must
be formulated in writing.

SECTION 3. ENTRY INTO FORCE AND PROVISIONAL
APPLICATION OF TREATIES

Article 24
Entry into force

1. A treaty enters into force in such manner and upon such date as it may
provide or as the negotiating States may agree.

2. Failing any such provision or agreement, a treaty enters into force as
soon as consent to be bound by the treaty has been established for all the
negotiating States.

3. When the consent of a State to be bound by a treaty is established on a
date after the treaty has come into force, the treaty enters into force for
that State on that date, unless the treaty otherwise provides.

4. The provisions of a treaty regulating the authentication of its text,
the establishment of the consent of States to be bound by the treaty, the
manner or date of its entry into force, reservations, the functions of the
depositary and other matters arising necessarily before the entry into
force of the treaty apply from the time of the adoption of its text.

Article 25
Provisional application

1. A treaty or a part of a treaty is applied provisionally pending its
entry into force if:

(a) the treaty itself so provides; or
(b) the negotiating States have in some other manner so agreed.

2. Unless the treaty otherwise provides or the negotiating States have
otherwise agreed, the provisional application of a treaty or a part of a
treaty with respect to a State shall be terminated if that State notifies
the other States between which the treaty is being applied provisionally of
its intention not to become a party to the treaty.

Author: international