Hi Ned, You`ll need to get it insured first. (Most insurance companies will let you transfer the policy over from your previous bike,(if it`s still current) for a poss` adjustment on price. Or, by the sound of it, you`ll need to get a new policy). For two reasons, ;- 1) The DVLA Data base will then automatically have your insurance for the bike on record. Once insured, you should be able to download & print a copy of your insurance certificate, (should you feel the need). Also, most importantly, the police won`t stop you for no insurance. (if they do,then you`ll be able to show them a copy of your policy ! ) ;- 2) The previous owner (Dealer), can then allow you to ride it ! (Once you show them the policy.) I`m assuming it`s got a current MOT ? So, with insurance & MOT,(on the data base) you can then, go online to get it taxed. (I`m not sure if your local post office does vehicle tax anymore).(There is no longer a requirement to display a "tax disc". They aren't issued any more, coz everything`s now on that data base !) You may have to wait a short time for your insurance to get registered on the data base. They can both now be paid monthly,(Tax & Ins`) (by setting up direct debits) although they work out a little dearer, (A few pence more per month). Or pay them in full, its up to you. After doing all this, then everything will then be on the DVLA Data base, (Ins` tax & MOT) and your all legal to ride.
Or, as I said before, (if it`s from a dealer) they`ll deliver it for a fee. and, that`ll give you more time to sort these things out. Alternatively, if you just want to "get it home" legally, get it on a trailer.( if one of your mates has one ? ) Or, your local bike shop might be able to help you out there, ( for a fee.) or hire a bike trailer. Or, if you, or a relative, has breakdown cover, they, (the recovery people), might get it home for you ? Hope this helps, Regards, Sircular.
P.s. You can`t tax a vehicle unless you`ve already got Ins` & MOT ! (&, yes, all you need is the Reg` number.)