[19] Designed by Babcock International, it is based on the Odense Maritime Technology (OMT) Iver Huitfeldt-class frigate hull and is marketed under the name Arrowhead 140.

[22][23][24] The 2010 Strategic Defence and Security Review (SDSR) authorised the Global Combat Ship (GCS) programme, which would replace the Royal Navy's thirteen Type 23 frigates.

"[34] A September 2017 graphic released by the Royal Navy stressed modular adaptability and flexible construction of the design for export opportunities.

Core requirements of the Type 31e frigate included a medium calibre gun, point defence systems, hangar and a flight deck for Wildcat or ten tonne helicopter operated by a crew of around 100 with space for 40 more personnel.

In October 2017, the Financial Times stated that ...officials inside the Ministry of Defence, the Treasury and Royal Navy have long resented the obligation, set a decade ago, to maintain skills and shipbuilding capacity at BAE's shipyards on the Clyde regardless of naval needs.

BAE submitted two designs, "Avenger", essentially an improved Batch 3 River-class OPV,[39] and "Cutlass", a significantly stretched and enhanced derivation of the Al Shamikh-class corvette.

[46] In late May 2018, Babcock, partnered with BMT, and Thales Group announced the "Arrowhead 140" design, based on the hull of the Danish Iver Huitfeldt-class frigates.

[55] In September 2022, John Howie, chief corporate affairs officer for Babcock International, stated that all five ships would be "delivered" to the Navy by 2028,[56] though other sources[who?]

[57] The AH140 design submitted by Babcock, BMT, and Thales is a development of the Iver Huitfeldt-class frigates in service with the Royal Danish Navy.

Type 31 is also now redesigned to meet NATO ANEP-77 Naval Ship Code and the stringent UK naval stability requirements as a key element amongst wider compliance with UK DefStan 02-900 General Naval Standard, amid a significant number of other UK naval standards.A further engineering paper published in 2024 by Babcock International explains that significant redesign of the 'parent' class was undertaken to create the Type 31 Frigate:[59] Based on Babcock’s ARROWHEAD-140 product line, and designed against Lloyd’s Register Naval Ship Rules, ANEP-77 and a significant number of UK Defence Standards (DefStans), Type 31 possesses capabilities, levels of survivability and features not found in previous escort classes such as the Type 23 and Type 45, themselves designed against previous generations of standards.The same paper goes on to explain the impact of these revised UK design standards:[59] The entire Type 31 platform has been re-designed to meet Lloyd’s Register Naval Ship Rules and the latest NATO / UK naval standards & regulations, which has introduced an increased capability in the redundancy and resilience of systems over legacy RN platforms including the Type 23 (the design of which pre-dates key standards such as ANEP-77) and many other contemporary Frigate designs.Babcock state that the design the Arrowhead 140 enables the hull to perform any of a wide range of roles specified by the customer such as:[60] AH140 also features a wide degree of flexibility in the component systems.

[68] Arrowyard is part of Babcock's business model for the AH140 of indigenous design as a means of building up a secure relationship with export nations and their industrial / societal base.

[72] In October 2023, Babcock formally began building its bid for the Royal New Zealand Navy (RNZN) and started looking for New Zealand-based small medium enterprises (SMEs) to develop a domestic supply chain.

[65][74][59] The procurement of the equipment fit for the Type 31 differs greatly from traditional practices, with designs decisions being made by the prime contractor [Babcock] or mission systems integrator [Thales] acting as the design authority rather than the Defence Equipment and Support (DE&S) organisation or Royal Navy personnel, in accordance to key characteristics laid down by the Ministry of Defence (MoD) for a general purpose frigate.

[75] The published Babcock engineering paper states:[58] ...The various rule sets and standards used worldwide to design ships deliver varying levels of capability into a warship, even amongst NATO navies.

The RN’s requirements have been honed by real-world and hard-won naval combat experience in the missile age; driving some of the most exacting standards to which a warship can be designed.

[75] In November 2022 the MoD placed a contract with BAE Systems Bofors ...for the supply of technical support, gun simulators to be commissioned into a Land Based Integration Facility (LBIF) for T31 Frigate and qualified 3P (programmable) ammunition for the 57 mm Mk3 and 40mm Mk4 naval gun systems that will be supplied with the five Type 31 General Purpose Frigates[77]In 2019, Forces News reported that the design would have Sea Ceptor (CAMM) missiles, an advanced air and surface surveillance and target indication radar such as the Thales NS110[78] and be able to operate either an AgustaWestland Wildcat HMA2 or an AgustaWestland Merlin HM2.

[79] Type 31 will have the first 4D Dual-Axis, Multi-Beam, Active Electronically Scanned Array (AESA) Radar to be fitted to a RN Frigate [Thales NS110].

Originally, the design would retain, but would however be "fitted-for-but-not-with" its 32-cell strike length Mark 41 Vertical Launching System and in its place was to be a Sea Ceptor 24-cell 'mushroom farm' in a similar configuration as found on the Type 23 frigates.

[86] Indeed, as of early 2025 the Mark 41 system was not yet funded and, if it went ahead, there was no information yet on numbers of missiles or cell packing arrangements for Sea Ceptor.

[87] In June 2023, the completed bow stem of the lead unit, HMS Venturer, revealed [59] that a bow-mounted sonar will also not be part of the initial build of the ship.

Defined by the latest high-TRL technology available that can be delivered into a class of warships in build now, and the various naval rules and regulations against which the ship was designed, Type 31 has the smallest effective and sustainable size of Ship’s Company possible for a 7,000 tonne General Purpose Frigate that is capable of global combat operations.On 9 December 2022, Indonesian state-own shipyard PT PAL Indonesia held the first steel cut ceremony for the first Fregat Merah Putih (Red White Frigate) at their shipyard in Surabaya.

[96][97] Thales SM400 Sea Master AESA radar On 16 August 2023, a steel-cutting ceremony took place for the first of the Wicher-class frigates, ORP Wicher.

At the MSPO 2024 defense expo, it was announced that the Wicher-class frigates will be fitted with Kongsberg's NSM anti-ship missiles instead of Saab's RBS 15 Mk 3.