How to book cheap flights: 14 tactics that actually work in 2025 — Budge

14 specific tactics for booking cheaper flights — with real numbers, honest debunking, and the one thing that beats all of them combined.

There is a specific kind of travel content that presents flight booking as a discipline requiring months of preparation, three alert apps, a spreadsheet, and the willingness to fly at 4am through a city you've never visited. Some of that is real. Most of it is overcomplicated. The gap between doing nothing and doing a few specific things is large; the gap between doing a few things and mastering every tactic is much smaller than the content suggests.

These are the tactics that actually move the price, with honest notes on the ones that don't move it as much as people think.

Flight booking fits into the broader trip planning sequence as the second major decision after destination, and the first thing you should actually pay money for — the complete guide to planning any trip from scratch covers where it sits relative to everything else. Here it gets the full treatment.

1. Be flexible on dates by 3 days either side — this beats everything else

Before any tactic: the single factor that reduces flight prices more than any hack, tool, or credit card programme is date flexibility. A three-day window on either side of your target travel dates can reduce fares by 30–50% on popular routes. Consistently. Without incognito mode, without alerts, without anything.

On a London–Tokyo flight that's pricing at £820 for your preferred date, moving three days earlier or later might find the same airline's same routing for £560. That's £260 saved before you've done anything clever.

Everything else in this guide is worth knowing. Nothing else saves you as much as this one variable.

2. Use Google Flights properly — most people use 5% of it

Google Flights has three features that most people never find:

The price calendar. On the search results page, click "Date grid" or "Price graph." This shows the price for every departure date across a month or two-month window as a colour-coded grid. The cheapest dates are immediately visible without manual searching. This alone justifies using Google Flights over any other search tool.

Explore. On the Google Flights homepage, leave the destination blank and click the map. It shows fares to everywhere from your departure city colour-coded by price. This is useful when you're flexible on destination or when you want to see which regions are accessible within a budget threshold. It's the best tool for answering "where can I go for £400?"

Price tracking. Hit the "Track prices" toggle on any route and Google will email you when the fare changes. Set it when you first start researching a route; by the time you're ready to book you'll have a feel for what's a real price versus an elevated one.

3. The incognito mode myth — debunked, but with a caveat

No credible study has demonstrated that airline or OTA websites raise prices based on your browser cookies. The claim circulates constantly in travel content and is almost certainly false as a general mechanism — airlines have no structural incentive to charge returning visitors more, and the pricing systems are too complex and variable for that to be a consistent tactic.

That said: flight prices change constantly, sometimes within minutes, because of yield management algorithms responding to booking demand in real time. If you search a flight, close the tab, come back twenty minutes later, and the price is different, that's not your cookies — it's the algorithm. Incognito mode won't prevent this and won't save you money. Booking when you find a good price is a better strategy than waiting to verify whether the price will hold.

4. Book long-haul 6–8 weeks out, not at the last minute

The "prices drop at the last minute" belief is partly a relic of the pre-internet charter flight era and partly true in a very specific context (leisure routes to beach destinations with high empty-seat risk in the final days).

For most long-haul routes, prices increase as the departure date approaches and business travellers fill the remaining seats at flexible fares. The data from fare analysis companies (Hopper has published this repeatedly) consistently shows the sweet spot for transatlantic and transpacific routes is 4–8 weeks before departure. For peak season travel or popular routes, earlier — 10–14 weeks — gives better availability even if not always the lowest price.

The last-minute window does sometimes produce deals: budget carriers trying to fill seats in the final 2–3 days occasionally drop prices sharply. This requires maximum flexibility (departing tomorrow, any destination) and can't be relied on for a planned trip.

5. One-ways vs returns on budget carriers

On full-service airlines, return tickets are almost always cheaper than two one-ways. On budget carriers — Ryanair, easyJet, Wizz Air, AirAsia, and their equivalents — the reverse is often true. Budget carriers price each direction independently, and two separate one-way fares frequently undercut the return option by 20–30%.

The practical implication: when searching budget carriers for a European trip, search each direction separately before assuming the return fare is the best option. Ryanair's interface, in particular, tends to bury the comparison.

The downside of separate one-ways: if your outbound flight is cancelled or severely delayed and you miss your onward plans, the airline has no obligation to rebook you because the tickets are not linked. This is a real risk on tight itineraries; build buffer time.

6. Positioning flights — how to access cheaper hub fares

Major airline hubs have dramatically more competition and usually lower fares than regional airports. If you live two hours from London Heathrow, the fare from Heathrow to Tokyo is likely to be meaningfully cheaper than the equivalent from Manchester — sometimes enough to cover the cost of a train plus a night in an airport hotel and still come out ahead.

The tactic is called a positioning flight: a cheap short-haul fare to a major hub, booked as a separate ticket, that gets you onto a cheaper long-haul flight. London, Paris, Amsterdam, and Dubai are the most useful European hubs for this. For US travellers, connecting through New York JFK or Los Angeles typically yields better transpacific fares than smaller regional airports.

Run the numbers specifically rather than assuming it works. On a Manchester–Tokyo route, the difference in base fare versus Heathrow might be £120. A train plus hotel to Heathrow costs around £80–£100. The saving is real but not large; on a longer route like Manchester–Sydney it can be £300+.

7. Error fares — how to actually catch them

Error fares are genuine pricing mistakes — a transatlantic business class fare for £180, a premium economy ticket misfiled at economy pricing, a routing where the ticketing system has miscalculated a combination. They exist, they're rare, and when they appear they're usually corrected within hours.

The practical approach: sign up for Scott's Cheap Flights (now Going), Secret Flying, or Airfarewatchdog. These services monitor fares and alert subscribers when genuine anomalies appear. Scott's has a free tier that sends the most publicised deals; the paid tier (~£25/year) sends more alerts faster, which matters because the best error fares last hours.

Two things to know about error fares: airlines are not legally obligated to honour them in most jurisdictions (they may cancel the booking, usually with a refund), so don't book non-refundable accommodation until the ticket is confirmed and a few days have passed. And the deals are route-specific and unpredictable — building a trip around "I'll wait for a cheap fare to Japan" is not a strategy.

8. The booking day and time effect — real, but modest

There is a modest and inconsistent pattern in the data suggesting that flights searched and booked on Tuesdays and Wednesdays price slightly lower than weekend searches — roughly 5–10% on domestic US routes in studies by CheapAir and others. The mechanism is that airlines often release fare sales on Monday nights, competitors match by Tuesday, and the lower fares are visible midweek before being adjusted.

For international routes from Europe and Asia, the pattern is weaker and less reliable. Treat it as a slight nudge rather than a reliable saving: if you're ready to book, Tuesday morning is a marginally better time than Saturday afternoon. It will not transform the price. Don't wait for a Tuesday if you've found a good fare on a Thursday.

9. Hidden city ticketing — works, carries real risks, use with caution

Hidden city ticketing is booking a flight that connects through your actual destination, then not taking the second leg. Example: London to New York direct is £650. London to Chicago with a New York connection is £480. You book the second itinerary and get off in New York, abandoning the Chicago leg.

The saving is real and the technique is legal (it violates airline terms of service but is not illegal). The risks are also real:

The airline can cancel your return ticket if they detect you've done this — they monitor for the pattern. Don't do it with a return fare; one-way only. You can't check a bag (it will go to Chicago). If your New York–Chicago leg is delayed, the airline may rebook you on a later connection rather than letting you off in New York. And the technique requires that the through-routing makes geographic sense — not all routes have useful hidden cities.

Used selectively, one-way, with carry-on only, for a route with a natural hub connection: the saving can be substantial. It's not something to build a regular booking strategy around.

10. Budget carrier add-on fees — always price the total, not the headline fare

A Ryanair fare of £25 becomes a different fare after seat selection (£5–£20), a checked bag (£20–£45 depending on when you add it), priority boarding if you want overhead bin space (£6), and a payment fee on some cards. The total is frequently comparable to a full-service carrier that includes a seat, a bag, and a meal.

The rule: always price the total fare with your actual requirements before comparing. A £25 headline versus a £95 all-in total is not a cheap flight. Use Google Flights' "Bags" and "Seat" filter options where available to standardise the comparison.

11. Use the right credit card — without the complexity

The credit card points ecosystem is genuinely valuable but presented in most content as requiring a second career to optimise. The simplified version:

One travel credit card, used for all spending, earning points redeemable for flights. In the UK, the Amex Preferred Rewards Gold earns Membership Rewards points transferable to most airline programmes; the welcome bonus of 20,000 points on spending £3,000 in the first three months is worth around £100–£150 in flights depending on how you redeem. In the US, the Chase Sapphire Preferred runs similar economics.

The value is in the signup bonus and the discipline of putting all spending through one card and paying it off monthly. The advanced optimisation — transfer partners, sweet spots, positioning for business class redemptions — is real but requires time to learn. Start with one card, get the signup bonus, and decide whether you want to go further.

12. Fly into secondary airports — sometimes

Ryanair into London Stansted adds 45 minutes and a train fare versus Heathrow. For a domestic short-break where the fare difference is £80, the secondary airport is clearly worth it. For a long-haul connection where you're already stressed about transit time and luggage, the marginal saving is less obvious.

The calculation: total door-to-door time and cost for each option, including ground transport. Stansted to central London on the Stansted Express costs around £19.40 and takes 47 minutes. Heathrow on the Piccadilly line costs around £5.50 and takes 50 minutes. The time is similar; the cost difference is £14. Worth knowing when you're evaluating a £40 fare difference.

13. The 24-hour cancellation rule (US-specific but useful)

US Department of Transportation rules require airlines to offer either free 24-hour cancellation or free 24-hour holds on bookings made at least seven days before departure. This applies to flights to, from, or within the US on any airline.

The practical use: when you find a good fare, book it, then spend the next 24 hours confirming accommodation and checking whether a better option appears. If something better shows up, cancel and rebook with no cost. EU consumer law offers similar protections on some routes; check the specific rules for your departure country.

14. Alerts, but done right

Price alerts work when they're set early and on specific routes. The mistake is setting an alert two weeks before you want to travel — by then you're getting alerts about a price that was lower three months ago and isn't coming back.

Set price alerts as soon as you've decided on a destination and likely date range — even if you're not ready to book for another month. The alert history gives you a reference price for what "cheap" actually means on your route rather than what feels cheap in the moment. A £520 London–Tokyo fare looks like a deal if you don't know the route was £460 six weeks ago and may drop again.

This is exactly the kind of research rabbit hole that Budge was built for — you can ask it follow-up questions about any of this and it remembers what you care about across the whole conversation. It's also worth having the travel planning checklist handy as a companion once your flights are booked — it covers everything that comes next in sequence.

The honest truth about cheap flight tactics

Every tactic in this list is real and some of them save meaningful money. None of them saves as much as tactic number one.

Date flexibility — three days either side of your preferred travel dates — consistently outperforms everything else because it works with how airline pricing actually functions. Yield management algorithms fill planes at the highest price the market will bear on each specific date. Popular dates cost more because more people want them. Adjacent dates cost less because demand is lower.

No hack changes this dynamic. Incognito mode doesn't. Tuesday bookings don't. Error fares appear too rarely to plan around. The tactics help you capture what's available; flexibility changes what's available.

If you can move your trip by a long weekend, do that first. Then use the tools.