O2 Double minutes Offer - how not to do it

Recently signed up for that O2 offer of double minutes. I only managed to catch it at the end of the month. Which is really bad time to do. I could be wrong but I think this is how it works.

They start billing from the start of the month, not when you join. So say you start the last day of the month. You get one day of your double minutes, then they close the billing period, and carry over your minutes but not your doubled minutes. So if you signed up for Active 150 for example. In month "2" you get
150 + 150 mins and 150mins only carried over from month 1. You lose 150mins even though you've only been signed up for a day. I got caught by this before, I should have known better. They should make it more obvious though.

So the best time to sign up is the first day of the billing period.

aircobra19 said:

You get one day of your your double minutes, then they close the billing period.

Click to expand...

I signed with O2 last year, and also received a 1 day bill (didn't sign for double minutes though). My billing period runs from 27th - 26th, not the calendar month.

Charges for rental or bundles are made in advance (calls are charged in arrears), does this explain the one day bill?

I'm only using that as an example of a billing period for the sake of taking advantage of offers like free minutes, double minutes, 6 months free, line rental etc. In effect they are chopping up to a month off the offer, whatever it is. Last time it was 6 months free, in effect you couldn't get 6 months free, unless you signed up on The first of the month. You got 5 months, plus x number of days.