Option 2
Go to the post office and apply for the Road Fund Licence in person, but you will require a copy of an original and valid insurance certificate.
If you tax online, you can still be fined for failing to display a tax disc. The offence here is failing to display a valid vehicle excise licence (tax disc). This is a DVLA offence and not a Police matter. The Police only inform DVLA.
erm i think you will find that this IS a police matter as i have had many fixed penalties through non dispay of rfl from the police for our fllet of NHS leased vehicles.