An HIA removal and an interchange are related, but they are not the same decision.

Which rules this page applies

The baseline is the International Rugby League 2026 International Laws of the Game, especially Section 4, Laws 1 and 2. It applies to the running, 13-a-side code—not rugby union, wheelchair rugby league, nines, tag or touch.

Where this page explains an assessment lasting 15 minutes, a concussion interchange card, Criteria One or Criteria Two signs, or a free HIA change, it is applying the Rugby Football League Medical Standards 2026 and RFL Match Day Operations Manual 2026 for the English professional competitions within those documents' scope. Those details must not be assumed for an NRL, community, junior or international match.

Thirteen on the field, four replacements, eight changes

IRL Section 4.1 limits each team to thirteen players on the field. Section 4.2(a) allows a maximum of four replacements to be nominated before the match; those names and the starting players' names must be given to the referee. The ordinary maximum is eight interchanges from those 17 named players.

An interchange is the act of changing an on-field player for an eligible named player. It is not permission to field fourteen. The referee or appointed interchange official must sanction the change, and each ordinary use of the process consumes one of the available interchanges even if the entering player appeared earlier.

The official controls when the replacement enters

IRL Section 4.2(a) requires the referee or appointed interchange official to sanction a change; the law book does not supply every sideline step. Under the RFL 2026 process, the outgoing player must leave before the replacement enters, the club is responsible for legal onside entry, and numbered cards record ordinary changes. Other competitions may use different administration.

IRL's note to Section 4.2 prevents an ordinary change during a play-the-ball. The exception is a replacement for an injured player who has left when play is stopped because of the injury. If a change is made while a kick at goal is about to be taken, the entering player cannot take that kick.

IRL Section 4 does not prescribe one automatic restart for every administrative breach. In the RFL process, an interchange official who notices a breach reports it to the touch judge and match commissioner; the club can then face an investigation and disciplinary action under the competition rules.

Injury does not automatically make a change free

Tactical changes and ordinary injury changes use the normal allowance unless a written exception applies. IRL Section 4.2(b) is explicit about blood: if the referee directs a bleeding player to leave for attention and the team replaces that player, the replacement counts among the eight.

A competition can create a free concussion interchange, a foul-play injury exception or a different limit. Those are competition provisions, not an unwritten general principle. IRL Section 4 itself does not say that every HIA removal is free.

The international law book supplies a trigger, not a full medical test

IRL Section 4.2(c) uses the result of a head injury assessment to decide whether an 18th player may be activated. It says the team medical officer must designate the affected player ineligible to return. It does not define the signs requiring removal, who performs a timed assessment, how long it lasts, whether the temporary change is free or the exact route for a cleared player to re-enter.

For a real match, first identify the competition. Then use its current medical policy for the assessment and its playing conditions for the interchange consequence. Calling every head-injury removal “a 15-minute HIA” is wrong outside a competition that has actually adopted that procedure.

Obvious concussion signs mean permanent removal

Under RFL Medical Standards 2026, Section E3, medical staff must remove a player who is diagnosed with concussion, shows listed signs or symptoms, or is suspected of having concussion. The RFL separates Criteria One signs from uncertain or possible Criteria Two signs.

Criteria One includes such findings as confirmed or suspected loss of consciousness, convulsion, balance disturbance, disorientation, definite confusion, memory impairment or a definite atypical behavioural change. A player with a Criteria One sign is diagnosed as concussed and permanently removed; a timed HIA is not used as a route back into the match. If Criteria One becomes apparent during an assessment, the player cannot return.

Uncertain signs start a 15-minute off-field process

Criteria Two covers uncertainty about a possible Criteria One sign, a head impact whose diagnosis is not immediately clear, possible confusion or behavioural change, and other signs or symptoms suggesting possible concussion. The player must leave the playing environment for an HIA.

RFL Section E4.1 measures 15 minutes from removal from the field. The assessment occurs in a quiet space, not pitchside. The first five minutes are supervised rest and allow replay review; a doctor then conducts a clinical evaluation including SCAT6. A normal SCAT6 does not compel clearance, and the doctor cannot override a below-baseline result merely by clinical preference. The player may return only if the doctor finds no concussion or suspected concussion, and never before the 15 minutes have elapsed.

The referee can request a check; the doctor decides the medical outcome

RFL Medical Standards 2026 allow a match official who is concerned about possible concussion to stop play, call on the medical team and request an examination. Medical staff may also ask the referee to require a player who refuses to leave to do so.

The referee does not pass or fail the HIA. The doctor decides whether an HIA is required, whether concussion is diagnosed and whether return is medically permissible. Match and interchange officials then control when an eligible player may enter under the operational rules.

“Free” describes the interchange count, not medical clearance

RFL Match Day Operations 2026, Section 12, lets a club use a concussion interchange card so another player can enter while the assessment occurs without immediately spending one of the eight ordinary cards. A normal interchange cannot later be relabelled as a concussion interchange.

The 15 minutes are real time from the moment the assessed player crosses the touchline. If cleared, the player must be ready at expiry and use the normal return process; the returning player may replace any teammate, not necessarily the temporary replacement. The latest permitted return is when that player's team has possession at the start of a new set of six. If the player is not ready then, needs other treatment during the assessment, is diagnosed as concussed or the assessment overruns, the free change becomes a normal interchange. The manual contains a limited extension process when concurrent HIAs or other demands prevent the doctor from completing both assessments on time.

In the last 15 minutes, the RFL still permits the free concussion change after all eight ordinary interchanges have been used. If play lasts beyond the assessment and the player is cleared, the player may return; if the player fails and no separate 18th-player route is available, the team finishes with twelve.

A second HIA removal ends that player's match under RFL 2026

RFL Medical Standards 2026, Section E3.1.1, says a player removed for an HIA more than once in the same match cannot return, whatever the outcome of the second assessment. That is a return restriction on the player; it is not by itself a second extra bench place.

If this is also the team's second player designated ineligible after an HIA, the separate 18th-player threshold may be met. The medical outcomes are counted at team level for activation, but each removed player's eligibility remains an individual medical decision.

Two HIA losses—or one qualifying foul-play injury

IRL Section 4.2(c) provides two activation routes:

1. HIA route: two players from the same team have been designated ineligible to return by the team medical officer following HIAs.
2. Foul-play route: one player is designated ineligible to return because of any injury, head or otherwise; an opponent's foul play caused it; and that opponent is sin-binned or dismissed for the foul play.

The second route is not limited to concussion. Equally, a penalty, an ordinary injury or an empty four-player bench does not by itself activate the 18th player. Activation makes the extra named player eligible to replace someone; it never raises the on-field maximum above thirteen.

Being placed on report can be enough in England's professional rules

The RFL 2026 Match Day Operations Manual, Section 13, is broader than the IRL baseline for the foul-play route: the 18th player can be activated where the medical officer makes the player ineligible and the opponent is placed on report, sin-binned or dismissed. IRL Section 4 names only sin-bin or dismissal.

Under the RFL process, the team doctor confirms the qualifying player or players to the match commissioner or reserve referee. Activation does not change the team's number of interchanges spent or remaining, but the activated player must then follow the ordinary interchange process. The medical designation is irrevocable for that match, and no second extra replacement is supplied if another player later becomes ineligible.

A free injury change is separate from 18th-player activation

RFL Match Day Operations 2026, Section 10.1, also excludes an immediate injury change from the eight when the player was directly injured by foul play, leaves at once, and the opponent is put on report, sin-binned or dismissed. If the injured player later returns, that later change counts. A player who failed an HIA is excluded from this particular return provision.

This is easy to confuse with the 18th-player rule. A free interchange preserves the count for a change involving the existing match-day players; activation makes the additional 18th player eligible. The factual tests and paperwork are related but not interchangeable.

There is no HIA return process in the RFL Community Game

The RFL's current grassroots concussion guidance states that there is no HIA in the Community Game. If concussion is suspected, the player is removed and cannot return that day. Return to sport follows the graduated return-to-play process and medical clearance requirements.

That is not a shortened version of the professional 15-minute process. It is a different safety rule for an environment without the same doctor-led protocol. Junior, school and other national community competitions must be checked against their own current rules rather than borrowing an elite television-match procedure.

Eight is not universal even within IRL competition

• Women's senior internationals: IRL approved a 2026 playing condition allowing ten interchanges rather than the Section 4 baseline of eight.
• RFL professional competitions: the 2026 Match Day Operations Manual lists eight interchanges from four replacements for Super League, Championship, Challenge Cup, 1895 Cup, Women's Super League, Reserves, Academy and WSL Under-19s unless the RFL directs otherwise.
• Rugby League World Cup 2026: IRL announced that the men's and women's tournament, starting 15 October 2026, will use the 2026 NRL/NRLW Premiership Rules and Interpretations, including the NRL/NRLW HIA policy. Do not apply the generic IRL or RFL procedure to those matches without the tournament rules.

A blood replacement uses the seventh interchange

Situation: an IRL-law match has used six interchanges. The referee directs a bleeding player off, and a named replacement enters.

IRL 2026 ruling: the team has used its seventh interchange. Section 4.2(b) expressly counts a replacement made because the referee sent a bleeding player off for attention. “Medical” does not automatically mean “free.”

A player passes the RFL assessment at 15 minutes

Situation: in an RFL professional match, a player with an uncertain head-impact sign leaves under the concussion interchange process, completes the five-minute rest and clinical assessment, and the doctor finds no concussion or suspicion of concussion.

RFL 2026 ruling: the player may return after—not before—the 15-minute period through the controlled interchange process. The player may replace any teammate. If ready and returned within the manual's window, the temporary change remains free; passing the assessment does not mean the original removal was unnecessary.

A second HIA removal cannot end in another return

Situation: an RFL player was assessed and cleared earlier, then suffers a separate head-impact event and is removed again.

RFL 2026 ruling: that player is out for the rest of the match regardless of the second HIA result. If another teammate was already designated ineligible after an HIA, the team can satisfy the two-player route for activating its 18th player.

On report produces different 18th-player answers

Situation: foul play directly causes a match-ending shoulder injury. The opponent is placed on report but is neither sin-binned nor dismissed.

IRL 2026 baseline: no 18th-player activation through the foul-play route, because Section 4.2(c) requires a sin-bin or dismissal.

RFL 2026 professional ruling: the on-report sanction can satisfy the RFL variation once the medical officer designates the injured player ineligible. The governing competition therefore changes the answer even though the incident is identical.

How to analyse an interchange or HIA

1. Name the competition, grade and season. Establish whether IRL, RFL, NRL/NRLW or another body's playing conditions control.
2. Separate the decisions. Is this an ordinary player change, a medical removal, a timed HIA, a permanent concussion removal or 18th-player activation?
3. Check eligibility and entry. Confirm the entering player was properly named, the outgoing player has left and the official has sanctioned entry.
4. Apply the count. Charge an ordinary interchange unless the controlling rules create a specific free-change exception.
5. Apply the medical protocol. Only qualified medical staff under that protocol decide diagnosis and return eligibility.
6. Test every 18th-player element. Count ineligible HIA players or prove the injury, causation, medical decision and required foul-play sanction.
7. Keep discipline separate. A report, sin-bin or dismissal may affect replacement rights, but it remains a distinct disciplinary decision.

Claims that are too broad

• “All rugby league has eight interchanges.” IRL's 2026 women's senior international condition uses ten, and domestic or modified competitions can vary again.
• “Every head knock gets a 15-minute test.” RFL Criteria One means permanent removal, while the RFL Community Game has no match-day HIA return process.
• “An HIA replacement is always free.” That depends on the competition's operations rules and on following its process.
• “Passing the HIA proves there was no reason to remove the player.” Removal is triggered by observed or suspected signs; assessment and clinical judgement decide what happens next.
• “The referee clears the player.” The referee controls play and can request examination; medical staff decide concussion and return eligibility.
• “Any foul-play injury unlocks the 18th player.” Medical ineligibility, causation and the specified on-field or report sanction must all be present.

Governing-body sources and effective versions

• International Rugby League — 2026 International Laws of the Game, Section 4, Laws 1–2
• International Rugby League — Amendments to International Laws 2026, effective 1 January 2026, including the women's senior international interchange condition
• International Rugby League — Rugby League World Cup 2026 competition-specific rules announcement, 29 April 2026
• Rugby Football League — Medical Standards 2026, Sections E3–E4
• Rugby Football League — Match Day Operations Manual 2026, Section C.10 and C.12–13
• Rugby Football League — current Community Grassroots Concussion guidance, “Concussion: What You Must Do”

Checked 27 August 2026 against the IRL 2026 law book and published 2026 notices, plus the RFL's 2026 professional medical and match-day documents. IRL supplies the baseline; the appointed competition's current playing conditions and medical protocol control any variation. This page does not substitute RFL procedure for NRL/NRLW or RLWC2026 policy.