An agent at a cancellation desk is working through a queue with a script and a shrinking number of seats. The script starts with one option. It is not usually the full extent of what the airline owes you, and the passenger who knows the difference tends to end up closer to it.

None of what follows requires an argument. It requires knowing that four separate things exist, and asking for the ones that apply.

Sixty seconds before you reach the desk.

Three things, in this order, while you are still walking.

1. Screenshot the reason. The airline must tell you why, in plain language detailed enough that you can understand how that reason caused the cancellation. Capture it now. If the stated reason changes later, having the original is what makes a claim simple.
2. Open the app and join the queue simultaneously. Rebooking happens in both places and seats disappear from both. Whichever resolves first, take it.
3. Decide what you want. The earliest flight anywhere, a specific route, or your money back. Agents respond far better to a clear request than to an open question, and the queue behind you will thank you.

The four asks.

These are separate entitlements, not alternatives. Which apply depends on the cause of the cancellation and on how much notice you were given.

Two of the four turn on whether the cause was within the airline's control, within its control but required for safety, or outside its control. That three-part test is set out in full in our companion guide to how the three categories work. The short version: compensation only in the first category, assistance in the first two, and a replacement flight or refund in all three.

Ask one: a flight that actually works.

The airline must get you to the destination on your original ticket, as soon as feasible, free of charge. Unlike a delay, which requires a three-hour wait before this obligation starts, a cancellation triggers it immediately.

"Next available" is constrained by a reasonable route requirement, and the Canadian Transportation Agency treats that as a real test rather than a formality. Its published example: where a direct flight is cancelled and the first option involves two connections and arrives 28 hours late, that may not be reasonable, because the extra time and connections further inconvenience passengers who booked a direct service. A slightly later direct flight would likely be the better option.

One local detail: a replacement flight can leave from the other building, so confirm which terminal your replacement flight uses rather than assuming it departs from where you are standing.

Ask two: your money back instead.

You are not obliged to accept a replacement flight. If the arrangements offered do not accommodate your travel needs, you are entitled to a refund of the unused portion of the ticket.

There is a stronger version. If you are no longer at your point of origin, at a connecting point for instance, and the trip no longer serves its purpose, the airline must refund the entire ticket as though no part of the journey had been taken, and fly you back to where you started, free of charge.

A voucher needs your written agreement

The default is a refund to whoever purchased the ticket, using the original payment method. An airline may offer a travel credit instead, but only where all three of these are true:

• The alternative never expires.
• The airline tells you in writing what the ticket was worth and that you may have that amount refunded to your original payment method.
• You confirm in writing that you know this and are choosing the voucher anyway.

Thirty days, whatever the format

Refunds must be provided within 30 days of the day the airline became obligated to provide one. That applies equally to cash, card credits and vouchers. And where the cause was outside the airline's control and it cannot rebook you within 48 hours, you can choose the refund at any point up until you are actually given a confirmed reservation. Waiting does not lock you in.

Ask three: food, and somewhere to sleep.

This entitlement is narrower than most summaries suggest, because two conditions must both hold. You must have been informed of the cancellation less than 12 hours before the original departure time, and have waited two hours or more past that time. It applies where the cause was within the airline's control, including causes required for safety, and not where it was outside its control.

Where it does apply, you are owed, free of charge:

• Food and drink in reasonable quantities. The regulator expects airlines to weigh the length of the wait, the time of day and the airport's location. Water and a snack may be reasonable for a short mid-afternoon wait; a proper meal is reasonable at mealtimes or after a long one.
• Access to a means of communication. Wifi, a phone at the gate, or a pre-paid calling card.
• Overnight accommodation, if you now face a night you would not otherwise have spent away. It must be reasonable given where you are, and must include transport to the accommodation and back to the airport.

If you live near Pearson, say so

This is the provision that matters most to anyone cancelled at Pearson who lives in the Toronto area, and it appears in almost nothing else written on the subject. The Canadian Transportation Agency's guidance says the airline should first discuss with you whether accommodation is actually needed, and that where a passenger lives near the airport it may be more convenient to stay at home. In that case the airline must simply cover your transportation home and back to the airport the next day.

Many travellers accept a distant airport hotel because nobody mentioned the alternative. If your own bed is forty minutes away, that is worth raising, and hotel transfers across Toronto and the GTA work equally well in either direction.

An airline may limit assistance only where providing it would further delay you, for example where handing out food vouchers would hold up boarding that is about to begin. Keep receipts for anything you arrange yourself, and confirm what will be reimbursed before you book it.

Ask four: the cash you’re separately owed.

Compensation for inconvenience is not a refund and not a rebooking. It applies where the cancellation was within the airline's control and not required for safety, and where you were informed 14 days or less before the departure time on your original ticket.

That notice condition settles a great many claims on its own. A cancellation announced a month ahead carries no compensation, however badly it disrupts you. One announced ten days ahead does.

That final row is the one people miss. Choosing the refund does not waive compensation where the cause was within the airline's control and not safety-related.

Compensation must be offered in monetary form, which can include cash, cheque, bank draft or electronic transfer. A voucher is permitted only if the airline states the monetary amount you are entitled to and the voucher's value in writing, the voucher is worth more, it never expires, and you confirm in writing that you are choosing it knowingly. The money goes to the passenger who experienced the disruption, regardless of who paid for the ticket.

Four situations with their own rules.

The aircraft was diverted

If a flight is diverted to an airport other than the one on your ticket, the airline must transport you to the ticketed airport, unless you decline that transport. Where the diversion is to another airport serving the same city, that may mean shuttles or taxis at the airline's expense. You are not expected to make your own way to Pearson.

You were rebooked into a lower class

Alternate arrangements must be comparable to what you bought, so far as possible. A higher class cannot attract a supplementary charge. A lower class requires the airline to refund the difference in cost for the applicable portion of the ticket.

You paid for extras you didn't get

The airline must refund any additional services you purchased but did not receive on the replacement flight, or that you had to pay for a second time. Seat selection, checked bag fees, lounge access and prepaid meals all qualify. They are small sums individually and routinely go unclaimed.

Your bags were already checked

They come off the aircraft and are returned to you, usually at a carousel or baggage service area. Unloading a full flight at short notice takes time.

Ask where to collect them before leaving the gate area, and take anything you will need overnight out of the checked bag if you get the chance. If a bag fails to appear, our guide on what to do if a bag doesn't come back covers the report to file before you leave the airport.

Tonight: getting out of Pearson.

Once the flight and the paperwork are settled, a practical problem remains: you are at an airport with luggage at an hour you did not plan for.

Work through it in this order:

1. Establish what the airline is covering. If accommodation is owed, transport at both ends is owed with it. Ask explicitly rather than assuming the voucher covers only the room.
2. Decide hotel or home. If you live in the GTA, raising the home option is legitimate and frequently better.
3. Confirm the address before you leave the terminal. Airport hotels are not all near the airport, and a voucher does not always name one until it is issued.
4. Arrange the ride once, for both legs. You will be doing this again in the morning, usually earlier than you would like.

Public transit remains available and perfectly usable for a light traveller heading into the city. With several bags, a family, or a 5 a.m. return, a booked vehicle removes a set of decisions at the point where you are least inclined to make them.

Tomorrow morning: getting back.

The return leg is where a pre-arranged transfer earns its place. Replacement flights cluster early, the night has usually been short, and the replacement itself can move again.

Obsidian Ride operates 24/7 dispatch with real-time flight tracking, so a further change to the replacement flight moves the pickup rather than stranding it. Put the new flight number on the booking rather than only a time, since a new flight number is information no tracking system can infer on its own. Service details are on the Pearson Airport chauffeur service page.

Before you set off, it is worth a moment to check whether the replacement flight is holding, and our guide to how early to arrive at Pearson sets out the buffer by flight type.

Next week: claiming.

You have one year from the cancellation to claim compensation with the airline that operated the flight, and it has 30 days to respond by paying or explaining why it believes nothing is owed.

Put the claim in writing with the flight number, date, route, the reason you were given and your actual arrival time at the final destination. Keep a copy of everything you send.

If the claim is rejected, the explanation matters as much as the decision. An airline must give a full and clear account: the reason for the disruption and why that means no compensation is payable. Where there were several reasons or several disrupted flights, it must set out each reason, the delay each caused, which flight was affected, the primary reason you arrived late, and which category that falls into. A one-line refusal citing "weather" does not meet that standard.

If the airline does not respond within 30 days, or the response is unsatisfactory, you can complain to the Canadian Transportation Agency, which will expect the airline to produce evidence for its categorisation, such as a weather report where weather was claimed. For international itineraries there may also be a separate claim for actual expenses under the Montreal Convention, with a two-year limit for court action. The binding text of all of this sits in the Air Passenger Protection Regulations themselves.

What an airline can legitimately refuse.

Worth stating plainly, because a guide that implies everything is always owed sets people up to argue badly at a desk.

• Compensation, where the cause was outside its control or within its control but required for safety. Weather, air traffic control instructions, security incidents and medical emergencies all fall outside.
• Compensation, where you were told more than 14 days ahead. The notice condition is absolute.
• Assistance, where the cause was outside its control, or where you were told more than 12 hours ahead, or where you have not yet waited two hours past the original departure time.
• Assistance that would further delay you, where providing it would hold up imminent boarding.
• A competitor booking by a small airline. Small carriers are not required to book you with an airline they have no commercial agreement with.

What an airline can never refuse is the obligation to get you to your destination or refund you, and the obligation to explain itself properly. Those apply in every category.

Pearson flight cancelled: frequently asked questions.