Thanks for the information, and also to clarify that the advance ticket for the outbound journey I have bought is one single booking from Wem and Brighton . I am just waiting now to do the same for the return journey.
Or do you mean I should’ve bought the outbound and inbound journey in one booking even if based on advance tickets?
If you are sure that Advances are going to be the best option, then I see no issue having separate transactions.
However, as a general principle, if you do have such separate transactions, I would recommend using the same retailer for both outward and return journeys; for example if there was an issue in one direction e.g. one of the trains was cancelled, causing you to change travel plans, then a good retailer would recognise the fact it is a return journey - as you had a corresponding booking in the other direction - and allow you to cancel or redate/retime both without penalty.
An advantage to having it as all one booking for both directions is that a good retailer will only charge one admin fee if you need to re-date/re-time the entire trip, e.g. if you changed both the outward and return legs.
TOCs typically charge admin fees on a per ticket basis; for a journey involving multiple tickets, that can get expensive. Trainsplit - who power the forum's site - only charge one admin fee for the entire booking, even if you change both the outward and return leg, and even if there are multiple tickets in each.
Of course if everything runs smoothly, none of this matters! But I have been made aware of many times when things haven't, so the above is always worth bearing in mind.
Don't forget if you want seat selection, Avanti allow it for their trains only, LNER for their trains only, TPE may do a similar thing and maybe one or two others do, but Trainsplit is the only one I know of that works with all reservable TOCs.
And some retailers outsource their customer services to people who don't understand GB rail ticketing, and/or have a habit of overcharging customers etc, such as Avanti in particular:
What is the best email address to use to contact Avanti Customer Services ? I booked an advance ticket on my phone via the Avanti site on 2nd August (only using Avanti site as I had an Avanti 10% discount code). During the payment stage I think the signal momentarily dropped and it...
www.railforums.co.uk
This morning, I bought two tickets on the Avanti website, one for today and the other for tomorrow, as separate transactions. ToD as for cross London travel. Both purchases went through, and I got collection references for both. However, when I went to the station, they couldn't find the...
www.railforums.co.uk
At the end of the day it's up to each individual to choose the option that works best for them, and there is no definitive answer, but I've never experienced poor service from Trainsplit and if anything ever goes wrong for any forum member who uses the forum's ticketing site, I would certainly be happy to put a word in to see if there is anything that can be done to help.
