The escort fleet comprises guided missile destroyers and frigates and is the traditional workhorse of the Navy. As of July 2021 there are six Type 45 destroyers and 12 Type 23 frigates in active service. Among their primary roles is to provide escort for the larger capital ships—protecting them from air, surface and subsurface threats. Other duties include undertaking the Royal Navy's standing deployments across the globe, which often consists of: counter-narcotics, anti-piracy missions and providing humanitarian aid.
The Type 45 is primarily designed for anti-aircraft and anti-missile warfare and the Royal Navy describe the destroyer's mission as "to shield the Fleet from air attack". They are equipped with the PAAMS (also known as Sea Viper) integrated anti-aircraft warfare system which incorporates the sophisticated SAMPSON and S1850M long range radars and the Aster 15 and 30 missiles.
16 Type 23 frigates were delivered to the Royal Navy, with the final vessel, HMS St Albans, commissioned in June 2002. However, the 2004 Delivering Security in a Changing World review announced that three frigates would be paid off as part of a cost-cutting exercise, and these were subsequently sold to the Chilean Navy. The 2010 Strategic Defence and Security Review announced that the remaining 13 Type 23 frigates would eventually be replaced by the Type 26 Frigate. The Strategic Defence and Security Review 2015 reduced the procurement of Type 26 to eight with five Type 31e frigates to be procured.