# Oyster card capping (zone 1 with one trip to zone 6)

How does Oyster capping between different zones work?

We're going to make one trip from Heathrow to zone 1 and then to travel in zone 1 only. As shown in this table travels between zones 1-6 are capped at £12,00. Travels in zone 1 are capped at £6.60.

My question is: will one trip from Heathrow to Zone 1 qualify the whole day as "Zones 1-6"?

If so, then it's cheaper to return Oyster card after arriving to zone 1 (£3.10 off-peak price) and then use a new Oyster card which will be capped at £6.60. (£6.60 + £3.10 = £9.70).

PS. Unfortunately (for this question) I didn't travel a lot in London (only two rides a day, ride to/from Heathrow included), so I could not prove nor disprove MJeffryes's answer).

• No point in returning it. You will get the £6.60 cap in Zone 1 even if your oyster is zones 1 - 6. Commented Jan 16, 2017 at 10:31
• If I travel in zone 1 only, yes. But what about the day with one ride from zone 6? @GayotFow Commented Jan 16, 2017 at 10:45
• Then you would get charged for for the Zone 6 cap. Think about it, any other way would not make sense and the Rail and Underground Panel would be flooded with complaints. Commented Jan 16, 2017 at 10:53
• Answer below from @MJeffryes summarises it nicely. Commented Jan 16, 2017 at 10:58

The Oyster system is designed to give the cheapest possible fare in the vast majority of cases. From TfL's fare information page:

As you travel, the system combines all the zones, times and fares recorded on your Oyster card so it can calculate the cheapest cap to apply. This means that sometimes you could be charged a cheaper off-peak cap even if you've travelled during the peak. This is because the system calculates the cost of:

• All the journeys you made during peak times
• All the journeys you made during off peak times

It then adds these together to work out which cap would offer the best value.

This isn't exactly referring to your situation, but it is similar. The Oyster system is designed to find the best combination of caps to minimise the fare paid.

• So, the card will be charged with £9.70? Okay, I'll check it out and report. Commented Jan 16, 2017 at 15:22

As I understand it TFL's website oversimplifies the situation.

My understanding is that currently there are two systems of capping, the "on card" system and the "back office system".

The on-card system is quite simplistic, it just looks at the fares you have accrued so-far, the zones you have travelled in so-far and whether or not you have travelled in the morning peak. The result is if you travel from zone 6 first then as far as on-card capping is concerned the zone 6 cap will apply.

The back office system is more advanced and will consider various combinations of caps and single fares to figure out what is cheapest.

My understanding is that if you use a non-discounted adult oyster card then your journeys will initially be subject to the on-card capping, but after your day of travel is complete the back office systems will re-calculate your travel. If the back-office capping comes out with a lower total than on-card capping then the back-office system will schedule a refund to be delivered to your card.

So assuming you travel from Heathrow on the Picadilly line I would expect you to be charged up to the zone 6 cap initially, but then get a refund when the system recalculates.

On the other hand if you travel from Heathrow on the Elizabeth line there will likely be no refund due to higher single fares from Heathrow on the Elizabeth line.