BS 10621:2017 specifies performance requirements and test methods for a thief-resistantmechanically operated single-point lock assembly (including locking plates, fixing screws, fittinginstructions, cylinders and protective furniture, where appropriate) that:

a) incorporates a lock conforming to BS EN 12209:2016 that, under normal conditions, can beunlocked from the inside without the use of a key, thereby allowing keyless egress;
b) can be changed to a secure (no egress) mode by a secondary positive locking action; and
c) is used in doors, window doors and entrance doors in buildings.

This standard covers only those thief-resistant lock assemblies that are intended for use in dwellingswhere there is an alternative escape route. It does not cover thief-resistant lock assemblies thatprovide keyless egress at all times since these are covered by BS 8621, nor does it cover thiefresistantlock assemblies that require the use of a removable key for egress since these arecovered by BS 3621.Cross References:BS 7398:1991BS EN 1303:2015PAS 24:2016BS EN 12209:2016 BS 3621:2017BS EN ISO/IEC 17065:2012BS 8621:2017305/2011/EUConstruction Products Regulations 2013Building Regulations 2010