Multi-region (US / UK / Middle East / South Asia), how does shared inventory work?

Magento Multi-Source Inventory (MSI), native since 2.3.0, was effectively designed for this case.

Sources (physical warehouses) per region: us_warehouse in New Jersey, uk_warehouse in Birmingham, me_warehouse in Dubai (free zone), in_warehouse in Mumbai or Delhi. Each source holds its own stock per SKU.

Stocks (shopping experiences) per region: US stock draws from US warehouse only; EU + UK stock draws from UK warehouse with EU fallback; Middle East stock draws from Dubai with India fallback; South Asia stock draws from Mumbai/Delhi. Customer geo-routes to a stock; stock aggregates inventory from its sources; cart shows accurate availability.

Pricing + currency: separate store views per region. US store in USD with tax-excluded prices, UK in GBP with VAT-included, UAE in AED, India in INR with GST. Same SKUs, different price tables, different checkout (Apple Pay + ACH in US, Klarna in EU, Tabby + Tamara in Middle East, Razorpay + UPI in India).

Festival calendar by region: Christmas is huge for US/UK but the same SKUs in Middle East stores serve resident Christian expats, volume is 1/20th but margins are higher (premium gifting). Diwali drives India + UK (Indian diaspora) but barely registers in Middle East unless the store serves Indian expat communities. The regional surge calendars are independent and need separate inventory pre-stocking.