BT has modified its Office Anywhere package to offer it as a bolt-on tariff to existing BT Business mobile phone contracts.

Office Anywhere was launched in April 2007 as a combination of data services and mobile applications aimed primarily at SMEs.

The new bolt-on comes in two flavours. A £10 option provides unlimited email, online access to Microsoft Office, mobile internet, unlimited calling between colleagues and unlimited VoIP calls to UK landlines via a Wi-Fi hotspot.

Users can share the minute bundles between Office Anywhere and other BT mobiles to help reduce wasted unused minutes.

For companies on a tighter budget a £5 option lacks the VoIP capability.

To promote the deal BT is offering new Office Anywhere customers £100 of airtime credit to use against Office Anywhere calls and line rental for a limited time, as well as three months of free line rental with BT Business One Plan.

As part of its Mobility Matters campaign, BT has launched a new guide to advise businesses on how to take advantage of mobile technology.

• BT Guide: Understanding the business benefits of mobile technology (PDF)