To be assessed as able to carry out an activity to the level described in a descriptor, a claimant must satisfy the descriptor “reliably”, that is: safely, to an acceptable standard, repeatedly and in reasonable time.


The meaning of "reliably" is defined in regulations.

Regulation 4(2A) of the main PIP regulations provides -

Where [a claimant's] ability to carry out an activity is assessed, [the claimant] is to be assessed as satisfying a descriptor only if [the claimant] can do so - (a) safely; (b) to an acceptable standard; (c) repeatedly; and (d) within a reasonable time period.

Regulation 4(4) of the main PIP regulations provides -

  1. "safely” means in a manner unlikely to cause harm to [the claimant] or to another person, either during or after completion of the activity;
  2. “repeatedly” means as often as the activity being assessed is reasonably required to be completed; and
  3. “reasonable time period” means no more than twice as long as the maximum period that a person without a physical or mental condition which limits that person’s ability to carry out the activity in question would normally take to complete that activity.

Source: Regulation 4 of the Social Security (Personal Independence Payment) Regulations 2013 (SI.No.377/2013), and regulation 4 of SR.No.217/2016 in Northern Ireland.

See also the section 2.2 of the Personal Independence Payment assessment guide for assessment providers.

NB - in Scotland, adult disability payment is replacing personal independence payment and the meaning of reliably is found in regulation 7 of the Disability Assistance for Working Age People (Scotland) Regulations 2022 (SSI.No.54/2022).

See also Social Security Scotland's guidance Reliability criteria for Adult Disability Payment


Case law

Commentary:​ The undefined term ‘to an acceptable standard’ has been considered in a number of cases particularly in relation to how pain affects the ability to complete an activity reliably. In the unpublished case of CPIP/2377/2015 the effects of pain, its severity and frequency, and the extent of any rests, are all considered relevant to the question of whether a claimant can complete a mobility descriptor ‘to an acceptable standard’. The effects of pain are also considered in [2016] UKUT 326 (AAC) where Judge Markus holds that even if someone may be able to carry out an activity repeatedly and within a reasonable time, they still may not be able to complete it ‘to an acceptable standard’ if they do so with difficulties such as pain or breathlessness. 

The meaning of 'safely' was considered in [2017] UKUT 105 (AAC) by a Three Judge Panel who found that it is not necessary to show that an occurrence of harm is 'more likely than not', but the likelihood of any harm should be weighed up against the severity of the consequences. | Add commentary or suggest an edit.