How do I configure ΦΠΑ 24% + Aegean island reduced rates in Magento?

Greece has three standard ΦΠΑ rates:

• 24%, standard rate (most goods + services).
• 13%, reduced (food, medicine, hotel stays, restaurants, transport).
• 6%, super-reduced (books, press, theatre tickets).

Plus a historical Aegean-island reduced rate for five specific islands (Leros, Lesvos, Kos, Samos, Chios) where rates were 17% / 9% / 4%, this has shifted in 2024 / 2025 with each annual finance law, so we lock the latest rule against AADE source before shipping. Some islands have lost the reduced rate; check current Νόμος + AADE circulars.

Magento configuration:

1. Create 3 (or 6) tax classes in Stores → Tax Zones & Rates (ΦΠΑ-24, ΦΠΑ-13, ΦΠΑ-6, plus Aegean-reduced variants).
2. Create tax rules scoped by Greek postcode ranges, Aegean-reduced is by postcode-prefix on those islands.
3. Assign each product’s tax class by category (food → 13%, books → 6%, electronics → 24%).
4. For B2B intra-EU, override to 0% if a valid VIES-validated AFM is on the customer.

Tax-inclusive prices on storefront (mandatory in EU B2C); tax-exclusive on B2B if opted-in.