It seems to me in looking to refinance there are a couple of loans that are great rates being 3.5% for 1 year before reverting after that time to the standard variable which is considerably higher than most other offerings.
Apart from the pain of paperwork, what is to stop me from taking on one of these loans and then refinancing in a year (to another attractive short term rate and so forth)?
From what I can see there are loan discharge and transfer fees from the current place and legal stuff and valuations from the new one, but often they may have deals where you can apply for free, or they give you a cashback (which is the case here, so it wouldn't actually cost us to switch)
Doing my sums it looks like it would be worth a few thousand difference to have the cheaper rate so it's definitely worth considering.
The last few places we've been with we had a great rate to start off with, and assumed we'd stay there however long, and over the next few years it has slowly increased so as to be higher than other rates you can easily get.
Does anyone do this on a yearly basis (or similar)?
Would it affect credit ratings to be regularly switching loans?
What am I not considering?
All the question you're asking come down to personally circumstances.
I wouldn't refinance every year, fee would eat into the calculated saving, every 2 -3 years maybe. Paperwork is a pain to to refinance every year too. And what price do you put on convenience?
If none of these matter to you and it's free to refinance, then go ahead I'd say if you have the time. Diligent always pay off :)