The Iraqi port city of Umm Qasr was the first British obstacle. A joint Polish-British-American force ran into unexpectedly stiff resistance, and it took several days to clear the Iraqi forces out. Fourteen Coalition soldiers and 30 Iraqi soldiers were killed. Farther north, the British 7 Armoured Brigade ('The Desert Rats'), fought their way into Iraq's second-largest city, Basra, on April 6, coming under constant attack by regulars and Fedayeen, while 3rd Battalion, The Parachute Regiment (the British Red Devils) cleared the 'old quarter' of the city that was inaccessible to vehicles. Entering Basra was achieved after two weeks of fierce fighting, which included the biggest tank battle by British forces since World War II when the Royal Scots Dragoon Guards destroyed 14 Iraqi tanks on 27 March.

Elements of 1 (UK) Armoured Division began to advance north towards U.S. positions around Al Amarah on April 9. Pre-existing electrical and water shortages continued throughout the conflict and looting began as Iraqi forces collapsed. While Coalition forces began working with local Iraqi Police to enforce order, a joint team composed of Royal Engineers and the Royal Logistics Corps of the British Army rapidly set up and repaired dockyard facilities to allow humanitarian aid to begin to arrive from ships arriving in the port city of Umm Qasr.

After a rapid initial advance, the first major pause occurred near Karbala. There, U.S. Army elements met resistance from Iraqi troops defending cities and key bridges along the Euphrates River. These forces threatened to interdict supply routes as American forces moved north. Eventually, troops from the 101st Airborne Division of the U.S Army secured the cities of Najaf and Karbala to prevent any Iraqi counterattacks on the 3rd Infantry Division's lines of communication as the division pressed its advance toward Baghdad.

A total of 11 British soldiers were killed, while 395-515 Iraqi soldiers, irregulars, and Fedayeen were killed.