Heathrow Express markets itself on speed: a non-stop 15-minute run from Terminals 2 and 3 to London Paddington, with trains every 15 minutes. It's genuinely fast for what it is. Whether it's the right choice next to a taxi depends on three things the headline speed doesn't tell you — what you actually pay, where Paddington leaves you, and how many people are travelling.
The fare is not what it looks like at first glance
Heathrow Express advertises fares "from" a low headline price, but that figure is an advance-purchase rate that generally needs booking a month or more ahead, and availability at that price is limited. Book on the day, or even a week or two out, and the walk-up single fare is considerably higher — as of 2026, commonly in the mid-£20s each way, with a premium class costing more again; check Heathrow Express's own published fares for the current price. That's a per-person fare. A taxi is a per-vehicle price: the quote is the same whether one person is travelling or four, which changes the comparison substantially for anyone not travelling solo.
This isn't a knock on Heathrow Express — advance-purchase discounting is normal for train travel — but it means the number most people remember from an advert isn't the number they'll actually pay if they're booking close to travel, which is exactly when most airport transport decisions get made.
Where it actually takes you
Heathrow Express goes to one place: London Paddington. The 15-minute journey time only tells the full story if Paddington is genuinely where you're going, or somewhere a short onward hop from there. For most other destinations — the City, Canary Wharf, a hotel south of the river, anywhere not on a direct line from Paddington — you're adding a Tube change or a second taxi leg once you arrive, with your luggage, on top of the advertised journey time.
A taxi's door-to-door nature means the destination doesn't change the fundamentals of the journey the way it does for a train that only serves one station.
Only two terminals get the direct service
Heathrow Express serves Terminals 2 and 3 directly. Terminal 5 has its own branch with a slightly longer run, and Terminal 4 requires changing at Terminals 2/3 rather than a direct service. It's a detail easy to miss when comparing headline journey times across terminals, and it's the kind of thing worth checking against your actual terminal before assuming the 15-minute figure applies to you — see our Heathrow terminal guide for pickup points by terminal.
Heathrow Express vs the Elizabeth line
If you're comparing options at Heathrow, it's worth being clear these are two different services, not two names for the same train. Heathrow Express is the faster, pricier, non-stop option to Paddington; the Elizabeth line is the slower, considerably cheaper, stopping service that also reaches Paddington (and beyond, into central and east London, without changing). Our Elizabeth line vs taxi guide covers that comparison in detail — if cost matters more to you than the extra speed, that's the train worth comparing against a taxi first, not Heathrow Express.
Luggage and the walk at either end
Heathrow Express has good luggage space for a train, but you're still managing your own cases from the platform, onto the train, and through Paddington's concourse at the other end — a bigger station than it looks on the way in, especially with an onward connection to make. A taxi removes that middle leg entirely: the driver handles the boot, and there's no station to navigate with bags at the far end.
So which is actually better?
As a rough guide:
- One traveller, booked well in advance, genuinely headed to or near Paddington — Heathrow Express at its advance fare is hard to beat on time and reasonable on price.
- One traveller booking last-minute — the walk-up fare narrows the gap considerably against a taxi, especially once an onward Tube fare or second taxi leg is added.
- Two or more travellers, any booking window, or a destination away from Paddington — a taxi is very likely the cheaper and less complicated option once the full door-to-door journey is counted.
As with any fare comparison, check the current Heathrow Express price for your booking window and party size against a fixed taxi quote for your actual destination before deciding — advance fares, off-peak windows and promotions change, so treat the figures above as a starting point rather than today's exact price. Our fixed-price airport transfer guide explains what a confirmed taxi quote actually covers, so you're comparing like for like.
Frequently asked questions
Q: Is Heathrow Express always cheaper than a taxi? A: Only reliably if you've booked well in advance as a solo traveller heading to or near Paddington — walk-up fares and any group larger than one narrow or close the gap against a taxi.
Q: What's the difference between Heathrow Express and the Elizabeth line? A: Heathrow Express is the faster, non-stop, pricier service to Paddington; the Elizabeth line is slower but considerably cheaper and continues further into central and east London without changing.
Q: Does Heathrow Express serve all four terminals directly? A: No — it runs directly to Terminals 2 and 3, with a separate branch to Terminal 5 and a change required for Terminal 4.
Q: Is the advertised low fare available if I book on the day? A: Usually not — the cheapest advertised fares are typically advance-purchase tickets booked a month or more ahead with limited availability; walk-up fares on the day are considerably higher.
Q: What if my destination isn't near Paddington? A: A taxi is usually the more straightforward choice — it's a single door-to-door journey, whereas Heathrow Express only gets you to Paddington and leaves the rest of the trip for you to arrange.