Everyone here should have an 11 digit number unless they live in:
Bolton
Bodmin
Blackburn
Camberley
Axminster
Buxton
Crediton
Ashburton
Dudley
Evesham
Honiton
Alton
Chard / Ilminster
Gretna
Huntingdon
Hungerford
Lancaster
Redditch
Kidderminster
Launceston
Northwich / Winsford
Matlock
Newbuty
Moretonhampstead
Sanqhar / Nithsdale
Skelmersdale / Ormskirk
St Austell
St Helens
Selkirk
Penrith
Tamworth
Oakhampton
Tivington
Workington
Worcester
Yeovil
Whitehaven
Whatton
Wincanton
Garstang / Wyre
Langholm
Hornby
Hawkshead
Grange-over-Sands
Sedbergh
Wigton
Raughton
Brampton
Appleby
Pooley Bridge
Keswick
Gosforth
All of the above have 10-digit numbers (although there are also 11-digit numbers in Lancaster, Penrith and Whitehaven, as well as the 10-digit ones), except for Brampton, which is the only place in the country with 9-digit numbers. [That's Brampton near to Carlisle, not the one in Cambridgeshire]. Everywhere else has 11-digit numbers.