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When the clock starts, pauses and ends

When the clock starts

The referral to treatment (RTT) pathway is the clock the 18-week standard is measured against, and it starts on the day your referral is received by the service you are being sent to, whether that is a hospital, a clinic or another provider on the NHS's list. If you book your first appointment through the NHS e-Referral Service, the clock starts on the day you make that booking. It is the referral itself that starts the count.

What pauses the clock

The clock can be paused where the delay is down to you, such as when you ask to change or delay an appointment you have been offered, or when you tell the provider you are not fit to be treated on the date offered. It starts running again once you are available. A pause like this sits inside your own pathway record, and it is one of the things a provider accounts for when it reports its figures for that month.

What ends the clock

The clock ends when your first treatment begins, when a clinician decides no treatment is needed, or when you are discharged back to whoever referred you without further action. Until one of these happens, your referral is an incomplete pathway: still open, still running, and still part of the group the monthly waiting-time figures describe.

These rules are not the same for every kind of referral. A routine consultant-led referral, a suspected cancer referral, a diagnostic test and an ambulance call each carry their own standard, their own clock start and their own pauses. Use our which waiting-time standard applies to me? tool to check which set of rules applies to your own pathway, with its source and the day it was checked.

Other standards: suspected cancer, diagnostic tests and ambulance calls

The 18-week standard covers routine, consultant-led referral to treatment. Three other pathways run to their own clock, and each is published separately.

Suspected cancer

A referral for suspected cancer is not measured against the 18-week standard. Cancer should be confirmed or ruled out within 28 days of the referral, under what the NHS calls the Faster Diagnosis Standard. This standard measures how long it takes to give the patient an answer.

Diagnostic tests

A referral for a diagnostic test on its own, such as a scan or an endoscopy, sits on a separate pathway again. NHS England publishes monthly figures for diagnostic waiting times apart from the 18-week referral-to-treatment figures, covering people waiting for the test itself rather than for a course of treatment.

Ambulance calls

An ambulance call is measured differently again. Response times are published monthly for each of the eleven ambulance services in England, broken down by call category, against the standard set for that category, so a Category 1 call and a Category 4 call are reported and judged separately.

If you are not sure which of these applies to the referral or the call you are dealing with, use our Which Waiting-Time Standard Applies to Me? tool. Choose the pathway you are on and it shows the published standard for that pathway, what it measures, when its clock starts and what pauses or ends it, each with its source and the day it was read.

What the monthly figures actually count

Most people on a waiting list have not been treated yet and have not been discharged. That is called an incomplete pathway, and it is the group the monthly waiting-time statistics are built from. If your referral has been made and you are still waiting for your first appointment, a test or your treatment, you sit inside this group, and the published figures for your provider and specialty describe people in the same position as you, for that month only.

The mean wait and the eight-in-ten figure

A mean wait is the average number of weeks across everyone still waiting on an incomplete pathway, for one provider and one specialty, in one month. It can be pulled upward by a small number of people who have waited a long time, so it will not always match what a typical patient on that list is experiencing.

The eight-in-ten figure (also called the 92nd percentile) measures something different: the length of time within which eight out of every ten patients on that pathway were seen. It is the figure the NHS's 18-week standard is measured against, because it describes most of the list. That 18-week standard applies to a routine, consultant-led referral; a suspected cancer referral, a diagnostic test, an A&E attendance and an ambulance call are each measured against a different published standard. If you are not sure which one covers your own referral, use our Which Waiting-Time Standard Applies to Me? tool: choose the pathway you are on and it shows the standard, what it measures and when its clock starts, each with its source and the day it was read.

Neither figure tells you what happens to any one patient. Both describe the whole incomplete pathway for a provider and specialty in a given month, and a patient waiting six weeks and one waiting sixty weeks both sit inside the same average.

Why the published month may not match your own wait

A monthly publication is a snapshot of everyone waiting at that point. Your referral date, your provider and your specialty determine your own position on the clock, and that position can move between publications as your appointment is booked, delayed or completed. The published figure tells you how that provider and specialty have been running recently; it does not tell you where your own referral currently sits, and it is not a prediction of your own appointment date.

Reading your own wait against the published figures for the same provider and specialty is still useful, because it shows whether the service is running close to the standard or well past it. The published month and the day the figure was read should always sit next to the figure itself, since a wait recorded several months ago describes conditions that may since have changed. If you want to see where your own referral sits against the 18-week clock right now, use our How Long Have I Been Waiting? tool: enter the date your referral was made and it works out the weeks waited and the date the standard was or will be passed, from the date you give it and nothing else.

Questions about symptoms, diagnosis or what treatment is right for you are for your GP, a pharmacist, NHS 111 or, in an emergency, 999. The Data and Sources page sets out where each waiting-time figure is published and how to check it, and the About Healthcare.uk page explains how those figures are kept up to date.

Worked example

How a single referral moves through the clock

Follow a referral date through the same clock that produces every published figure, and the gap between your own wait and a provider's monthly average stops being a mystery.

  1. Your referral date starts the clock

    The clock that measures your wait begins on the day the hospital or clinic receives your GP referral. While you are waiting, this is called an incomplete pathway: a referral that has not yet ended in treatment or discharge. It is this same clock that any published waiting-time figure for your specialty is measuring against. The How Long Have I Been Waiting? tool takes the date from your own referral letter and works out where you sit against it.

  2. Weeks accumulate until something pauses or ends the clock

    Each week adds to your count unless something specific happens to it. A pause stops the count temporarily and a recorded reason, such as a delay you have asked for yourself, has to sit behind it. An end stops the count for good, whether that is treatment starting or your case being closed back to your GP.

    The trust holding your referral decides whether a pause applies, using its own record.

    Clock keeps running

    Nothing has paused it, so every week still counts toward the 18-week standard.

    Clock pauses

    A recorded reason stops the count until the pause is lifted, then it resumes from where it left off.

  3. The 18-week point arrives, or treatment does

    One of two things happens first for any given referral. Either you are treated and the pathway closes, or the 18-week point passes while you are still waiting. Which one comes first for you decides what you can ask for next. This example follows the 18-week standard that applies to a routine, consultant-led referral. If your own referral is for a suspected cancer pathway, a diagnostic test, or came through A&E or an ambulance call, the standard and the clock rules behind it are different. Try our which waiting-time standard applies to me? to see the standard that applies to your own pathway, with its source and the day it was read.

    Treated first

    The pathway ends, and the wait recorded against you is the number of weeks from referral to that treatment date.

    18 weeks pass first

    Your pathway stays open as an incomplete pathway, and the NHS's own guidance on what you can ask for becomes available to you from that point.

  4. A monthly figure sits alongside your count

    Each month a provider publishes a mean wait, the average across every patient still waiting in that specialty, and an eight-in-ten figure, sometimes called the 92nd percentile, which is the point below which eight in ten of those patients' waits fall. Both describe everyone on the list that month. Your own week count can sit above or below either figure without that telling you anything about your particular pathway.

A monthly figure a provider publishes is a dated snapshot of everyone on its list that month. See how each figure on this site is sourced and dated on the data and sources page.