3V Prepaid cards are available as gift cards from some supermarkets and other gift card vendors. They are available in denominations of £25.
Cards are activated online via their website and are easy to register. Once the card is registered, a Visa number is provided and multiple cards can be managed via the website account.
Customer service is good on the odd occasion I have had to contact them, and is via email. They have responded within 48 hours of the query each time.
Negatives however is that the cards cannot be used for financial transactions, and if your merchant insists on Verified by Visa, this is not supported so your transaction can be rejected. I have discussed this with 3V who say that no Verified by Visa support should not lead to a transaction rejection, however there are online sites (usually game/console/DVD/Blu Ray) that I have found will not allow the transaction to proceed at all if there is no Verified by Visa support.
Also the cards are designed for remote transactions only, there is no physical card you can take to a shop and the balance cannot be recharged.
Also your maximum purchase is limited to £25 unless you merge cards together to make a single card with a larger balance. Unfortunately this costs money for each card you merge rather than a single fee to merge a bunch of cards.
One positive is that the cards can be used with Amazon and Paypal, the latter increases acceptance and I have successfully used it for some sites where Verified by Visa is a mandatory requirement.
Good customer service, easy to use, Amazon/Paypal accepted
Financial transactions out, no VerifiedbyVisa, costs to merge