Glasgow to Penrith by train

The train service between Glasgow and Penrith is split between trains operated by Avanti West Coast and trains operated by Trans Pennine Express.

Each of these operators doesn't provide an hourly service, so the pattern of departures can be fairly random.
It can vary from a total of two departures per hour to gaps of more than 90 minutes between trains.

Though TPE (Trans Pennine Express) typically provides the most frequent train service from Glasgow to Penrith.

However, the Avanti West Coast services have the faster journey times; they're typically 15 mins quicker than the TPE (TransPennine Express) services.

Final Destination: London Euston or Birmingham New Street (Avanti West Coast); Manchester Airport (Trans Pennine Express)

All trains also call at: Carlisle

Choosing a departure

As there are two operators which provide the trains on the Edinburgh to Penrith route, the recommendation is to use the National Rail booking service when looking up this journey.
By doing so you'll have an overview of the ticket times and prices of all departures, no matter which company is operating each departure, and you will also avoid any booking fees.
One company doesn't always offer the cheapest fares on this route, so it's worth making an easy comparison across all departures.

Booking Advance Tickets

If you want to travel at the cheapest possible price, look for the 'Advance tickets', though the three key things worth knowing about booking and using 'Advance' tickets are:
(1) Your ticket(s) will only be valid on the departure you selected when making a booking
(2) A fee will be payable if you want to transfer your ticket(s) to a different departure ahead of your travel date - and you will only be able to choose alternative departures operated by the same company that's providing the service you were originally booked on to.
(3) This type of ticket can't be refunded if you subsequently change your travel plans, or miss the train in circumstances not to do with a connecting train.
(4) If the train you are booked on is delayed, you cannot then just hop on an alternative train operated by a different company.

Reservations

When you book an Advance ticket for a Glasgow to Penrith train journey, you will be automatically assigned a seat(s), but if you book the other types of ticket ahead, you can request a complimentary reservation - more info on this
Tickets can now be booked online up to a couple of hours prior to departure

However, if you buy Off Peak or Anytime tickets just prior to boarding at the station, a seat reservation WON'T be automatically included with your booking.

That's because reservations at stations need to be booked by the end of the previous day for morning departures and around two hours ahead for afternoon/evening departures - so also keep that in mind if you will be using a rail pass, including a Britrail or Eurail pass.

Travelling on Monday - Friday

Tickets are usually available 12 weeks ahead of the travel date.
However, when you look up a journey you may see dates further ahead on the calendar, but you'll be informed that tickets aren't yet available for those dates.

Travelling on Saturday-Sunday

Tickets are usually available 12 weeks ahead of the travel date, but maintenance work on the route is periodically undertaken at weekends and if it is scheduled on your travel date, it can affect when tickets will be released for sale.

If you're looking up a journey less than 12 weeks ahead and tickets aren't available, it can be a good indication that works will be impacting on your travel date.
It can be worth checking this on the National Rail website