Pre-purchase Collection train tickets

Southeastern's website was one of the few TOC websites that I had an issue making a purchase through. Try setting up an account and purchase your tickets through Virgin -- https://www.virgintrains.co.uk/

They do not have the issues with US cards that some other TOCs have.

I booked with Southern (southernrailway.com) from Brighton to Victoria Station in London for this July, using Paypal.

Yes, many times for many different train companies, along with squillions of other regular travellers.

• I don't know what country you are from (you don't say), but did you tell your credit card company you were making purchases in the UK? If not, they may have blocked the transaction as suspicious.

• I wouldn't bother getting those tickets in advance. I just checked on https://www.nationalrail.co.uk/ the tickets cost £8.20 and are valid on any train. That is the price you pay at the station, no discount or other advantage in buying in advance.

Thanks to all-we tried inputting phone # & 'postal code' (Rochester NY) but those were not accepted.

Was purchasing advance tickets as had been advised on Steves' plus elsewhere that it's less expensive. So remain confused but may try those other train line options such as Virgin.

Was purchasing advance tickets as had been advised on Steves' plus elsewhere that it's less expensive.

Long distance train tickets are often cheaper if bought in advance, include reserved seats, and can (rarely) sell out at busy periods if all seats are taken.
None of this applies to Ashford to Canterbury. It is a local run, there are 3 departures per hour, it takes between 16 to 22 minutes (depending on which intermediate stations it stops at). Hardly enough time to get seated ☺
It is used by locals to make spontaneous trips for shopping, visiting friends, going to the pub or whatever. Not the Orient Express.

For £8.20 (from the machine at the station), you can get on any train, and sit anywhere you want.

Take Chris F's advice.

Advance ticket fares and purchases are ideal for when there's a significant savings over the anytime fare for long-distance routes.

Everyone, thanks! I see there's no need to worry about advance tickets on the "milk run" as we used to call it.

Much appreciated-