If you buy a a second hand truck whether from a dealer or privately can you call out the main dealer if you breakdown, obviously you will have to pay for this but do you need to set up an account with your local dealer? and which manufacture provides the best call out service abroad aswell as the UK
if you set up an account at your local dealer for the make of truck you have, you can call on their breakdown cover, such as DAFAid, Volvo assist, or whatever they may be called.
can’t really answer your second question, i don’t run abroad 
BigE:
If you buy a a second hand truck whether from a dealer or privately can you call out the main dealer if you breakdown, obviously you will have to pay for this but do you need to set up an account with your local dealer? and which manufacture provides the best call out service abroad aswell as the UK
Yes, as long as you’ve a credit card and settle the account upon completion of the work, I done that in the past with Merc. There is a scheme where you can pay a montly fee, and all breakdown call outs to your truck and trailer is covered by independant commercial repairers local to your breakdown location, you just pay for parts, I remember Tramper giving out this info to someone asking a similar question to you.
Thanks guys question answered