States that are already members of a customs union (e.g., the EU) and whose entire customs regime is bound to superior law shall be considered as having limited customs autonomy.They may nonetheless join the GPP customs exemption provided that:
they have bilateral leeway for tariff reductions and actively make use of it, and
they commit to actively promoting the GPP customs objectives within their union.
In the event of a conflict with existing customs agreements, an official notification to the GPP is required. This will be recorded in the agreement to ensure transparency and legal certainty for other Member States.
