Greenwich commuters will finally be able to use Oyster pay-as-you-go for rail journeys from 2 January, after years of negotiations between Transport for London and the capital's private rail operators.
But there's a sting in the tail for some rail passengers, with cheaper off-peak tickets withdrawn for those who don't use Oyster cards, and higher fares for all in the evening rush hour.
Many local passengers have been using Oyster on local rail services for some time, but because they have Travelcards loaded onto their tickets.
Now all passengers will be able to use the smartcards to pay for individual journeys, just as Tube and Docklands Light Railway users have done for the past six years. On the Greenwich line, this means the cards will be as valid as far out as Slade Green, on the edge of zone 6.
From 2 January, passengers who don't use Oyster cards will be charged a flat rate of £2.40 from Greenwich and other zone 2 stations to London Bridge, Waterloo East, Charing Cross or Cannon Street, with a return costing £4.30.
Those travelling from Maze Hill or Westcombe Park, in zone 3, will be charged £3.10 single, or £5.30 return.
But passengers who do use Oyster cards will be charged cheaper rates, with all journeys being charged as singles.
From Greenwich, passengers for central London will have to pay £2.10 if their journey takes place in the morning or evening rush hour - between 6.30am and 9.30am, or 4pm-7pm.
If their journey avoids those times, or is at weekends, then they'll be charged £1.70.
Oyster card holders from Maze Hill or Westcombe Park will pay £2.60 for a peak journey, or £2 off-peak.
The new system also means passengers can combine rail and Tube/DLR journeys. If their journey does not include Zone 1, it's at no extra cost. Someone travelling from Maze Hill to South Quay DLR via Greenwich would be charged £1.80 in peak hours, £1.50 at other times - the same fare as Maze Hill to Deptford.
But there's an extra £1.10 added for journeys through zone 1 - so Maze Hill to Goodge Street will cost £3.70 or £3.10 single.
A cap will apply on fares, so passengers making different journeys during the day will find they pay no more than the appropriate rate for a one day Travelcard.
For people using paper Travelcards or season tickets, it's business as usual.
However, the Oyster deal will not make travel as convenient as some users might like.
Passengers with Travelcards who need to travel outside their zones will be expected to get a free "Oyster Extension Permit" from a ticket machine or ticket office, or Oyster shop, before they travel to a National Rail station.
So someone with a zones 1-3 Travelcard will need to get a permit before travelling to Abbey Wood, in zone 5, for example. However, permits can be picked up weeks or months in advance, and will stay on Oyster cards until they are actually used.
Gold Card holders - who have annual Travelcards - will still have to buy paper tickets to get their usual one-third discount on tickets outside their zones.
And all passengers wanting to travel to Dartford or deeper into Kent will need to buy a paper ticket as normal.
As part of a separate agreement, Thames Clippers river services have already started to accept Oyster pay-as-you-go tickets, offering a 10% discount on normal cash fares, while Travelcard holders will get a 30% discount.
A £5.80 single ticket from Greenwich or QEII piers to central London will be reduced to £4.80 with Oyster PAYG, or £3.55 with a Travelcard.