There is one national telephone number charged at local rate. Calls will be geographically routed to the appropriate Pension Centre using caller line identification (CLI).
Each Pension Centre will:
+ work out the amount of State Pension and Minimum Income Guarantee that you are entitled to;
+ work out the amount of Pension Credit you are entitled to;
+ arrange for the local service to provide a face to face service if you are not able to phone or write to your Pension Centre;
+ pay your entitlements to you and answer questions over the phone and by post (and by e-mail where possible);
+ tell you how you can access other pension-related entitlements and services;
+ work in partnership with other local organisations to deliver pension-related services. 

www.thepensionservice.gov.uk  

Anyone with an enquiry about their pension entitlement 

By telephone (calls automatically routed to your nearset Pension Centre) 

No (but may be at some local Pension Centres) 

Service free, calls charged at local rate