However, specifically, a SOR notice did not actually stop your vehicle having vehicle tax. It was, as I read it at the time, quite valid to have vehicle tax and be off road, thus removing insurance requirements. And if you only needed to be off road for a short period this was a lot less hassle, and could even be cheaper, than getting a partial vehicle tax refund and re-taxing when back on the road (and insured).
Back in those days you could easily prove you had tax as you had a real tax disk.
I can only assume they have changed the law, as it seems that sending a SOR notice causes you to get a partial refund of the vehicle tax and no longer be taxed.
I am trying to find my way through the minefield of the legislation changes to work it out, and see if one can declare a vehicle off road without cancelling/ceasing the road tax. So far I am failing to find the details that cover this specifically. The problem is that, without an actual "tax disk", they can say you are no longer taxed and you have no proof otherwise.
The reason this came up is my daughter did declare her vehicle SORN for a short period, in the middle of the year, having paid for a year's road tax in January. And was apparently unaware that this meant she no longer had road tax. After all, she paid for a whole year, why would she not have road tax for a whole year?
Now, I can understand that some people may well want to declare SORN and request road tax be stopped and partly refunded - maybe that is what she inadvertently did. The "form" that DVLA have is an "application" of some sort and not simply a "notice" now. Something to try and find out for sure, and next time only send the notice, and not apply for the vehicle tax to be stopped.