o2 Best for Business sim only

If your existing mobile handset is fit for purpose, and you simply need to reduce the cost out of your business, then the O2 simplicity tariffs could be right for you. Inclusive minutes and texts as with our standard, handset inclusive tariffs, just cheaper.
Free calls to any O2 mobile included. Call your colleagues', customers, supplier's, friend's & family for free if they’re on O2.
Usage limits apply; each person in your account can make up to 2000 minutes a month of calls to any O2 mobile. After this, any calls to O2 mobiles will be deducted from the inclusive minutes of your tariff and if you have used all your inclusive minutes then any O2 calls are only 8p per minute
More Value & Flexibility
With inclusive UK minutes & texts to any UK network at any time, but with the added flexibility of a 30 day rolling contract term.
And, if you decide you need to upgrade and take a handset, you can transfer to one the 02 standard Best for Business tariffs whenever it suits you.