The question they're asking is "What's the net benefit to Deloitte?"Benefits would include your personal engagement. It's difficult to quantify this, mainly because to do so would be to suggest that you're not giving 100% already. Also, if you're required to work on projects in the NE, you'd be cheaper than bringing someone up from London.Costs presumably include the administrative overhead to complete transfer paperwork, any additional costs of office space in Newcastle, travel and accommodation costs when your projects are in London (even if these are passed on to the client, they inflate your effective cost-competitiveness), costs of communication and supervision if there isn't a team in Newcastle for you to slot into.If there is a team in Newcastle that you'd be joining, you should also make the business case for them to receive you, in order to create a "pull" factor within Deloitte for the move.