oakbookkeepingservices.co.uk Your local Reading based Bookkeeper.
"More than 250,000 high earners have already opted out of receiving child benefit but several hundred thousand others who missed a deadline to declare they will no longer qualify will now have to fill in self-assessment tax forms." According to BBC online.
Its too late now to register to opt out as yesterday was the deadline. However it's a lot easier to fill in a self assessment form and pay it back in January 2014 than to try and get it back if your financial situation changes which in the current climate is a possibility.
Just make sure you don't spend it by setting up a standing order to pay it straight into a high interest savings account ready to pay back.