Hello, I might be a bit late, but this may help others. The changes are something that we have been asked about a lot recently. This, and the linked documents, should help to clarify things: http://soh.co.uk/will-your-08-numbers-be-against-the-law.aspx#.U0v9CSgxeRI
In summary, a couple of things to bear in mind:
1. Not all sectors (financial services, package holidays and timeshare for example) are currently required to change their service numbers.
2. Several regulatory bodies (the FCA and the Cabinet Office for example) are currently considering their positions on service numbers as well.
3. There is a great deal of public misgiving and uncertainty about certain types of 08 numbers (the reason why Ofcom suggested the change in the first place). Even if you are not required to change them by law you may wish to consider doing so to avoid this.
To help organisations make the change we've asked ICM to carry out some research into what customers think about different number types (the new 03 numbers included). Watch out for the results next week.