Iberia is Spain's flag carrier and an IAG oneworld member, operating from Madrid Barajas Terminal 4/4S with one of Europe's densest Latin America networks. For UK travellers, Iberia is often the most efficient oneworld routing to Buenos Aires, Lima, Santiago, and São Paulo — Avios redemptions on Iberia metal from London frequently route via MAD at lower surcharge than BA long-haul.
Long-haul business class on the A350 uses a reverse-herringbone seat with direct aisle access — competitive though not class-leading versus Qsuite or Club Suite. Iberia excels in Spanish catering on Europe-origin sectors and the Dali VIP Lounge at Madrid Terminal 4S, which serves business and oneworld Emerald/Sapphire on international flights.
Iberia Plus shares Avios with British Airways Executive Club and Aer Lingus AerClub under IAG Loyalty. UK-based collectors can earn and redeem Avios on Iberia flights, and partner availability from London to South America via MAD is among the best uses of Avios in the oneworld alliance.
UK261 applies to UK-departing Iberia flights. Pair with /airports/madrid and compare against BA direct to Latin America for routing decisions. Iberia wins on Avios value and connection breadth; BA wins on direct LHR departures where available.