By ‘trial’ transactions in this case I mean the likes of the £1.58 that iTunes appears to bill and then rescind just to prove that a customer exists.
In the specific iTunes case on my card, it took just less than a week to withdraw the £1.58. Fine by me (and anyway the timing is an Apple issue) but I was surprised that rather than withdrawing the original £1.58 pending transaction, I got a £1.58 credit.
Clearly, that makes no financial difference to me (other than a slight discontinuity in my monthly spending figures) but it does mean that I now have a pending transaction that will presumably never clear and a credit of some money that was never really gone from the account in the first place.
While I accept that this is a one-off from my viewpoint (for iTunes, at least), from a banks viewpoint this may occur for most customers so I would hope that a slicker method of indicating a withdrawn ‘test’ could have been considered.