England

Master Locks in Bedfordshire (Bedford, Luton, Dunstable, Leighton Buzzard, Biggleswade, Sandy, Ampthill, Arlesey, Flitwick, Houghton Regis, Kempston, Linslade, Potton, Shefford, Stotfold, Wixams, Woburn Sands, )
Master Locks in Berkshire (Reading, Bracknell, Maidenhead, Newbury, Windsor, Wokingham, Abingdon, Ascot, Crowthorne, Earley, Eton, Hungerford, Sandhurst, Thatcham)
Master Locks in Buckinghamshire (Aylesbury, Milton Keynes, Slough, Buckingham, High Wycombe, Beaconsfield, Burnham, Chesham, Fenny Stratford, Marlow, Newport, Olney, Princes Risborough, Stony Stratford, Wendover, Winslow, Woburn Sands, Wolverton)
Master Locks in Cambridgeshire (Cambridge, Wisbech, Ely, March, Whittlesey, Chatteris, Linton, Fulbourn, Godmanchester, Hanley Grange, Huntingdon, Littleport, March, Northstowe, Ramsey, St Ives, St Neots, Soham, Wisbech)
Master Locks in Cheshire (Chester, Stockport, Ellesmere Port, Birkenhead, Wallasey, Runcorn, Macclesfield, Crewe, Warrington, Sandbach, Northwich, Nantwich, Middlewich, Malpas, Knutsford, Frodsham, Congleton, Bollington, Alsager,)
Master Locks in Cornwall (Bodmin, Truro, Camborne, Redruth, St. Austell, Falmouth, Penzance, Newquay)
Master Locks in Cumberland / Cumbria (Carlisle, Whitehaven, Workington, Penrith, Keswick, Brampton, Windermere, Wigton, Ulverston, Silloth, Sedbergh, Milnthorpe, Millom, Longtown, Kirkby Stephen, Kirkby Lonsdale, Harrington, Egremont, Cockermouth, Cleator Moor)
Master Locks in Derbyshire (Derby, Chesterfield, Ilkeston, Swadlincote, Buxton, Matlock, Ashbourne, Alfreton, Bakewell, Bolsover, Darley Dale, Dronfield, Dronfield Woodhouse, Eckington, Glossop, Glossopdale, Hadfield, Heanor, Ilkeston, Killamarsh, Langley Mill, Long Eaton, Matlock, Melbourne, Netherthorpe, New Mills, Newhaven, Renishaw, Ripley, Sandiacre, Shirebrook, Staveley, Swadlincote, Tansley, Whaley Bridge, Wirksworth)
Master Locks in Devon (Exeter, Plymouth, Torquay, Paignton, Barnstaple, Tiverton, Newton Abbot, Tavistock, Axminster, Bideford, Chagford, Chudleigh, Colyford, Dartmouth, Exmouth, Great Torrington, Hartland, Ilfracombe, Kingsbridge, Okehampton, Salcombe, Sidmouth, Tavistock, Topsham, )
Master Locks in Dorset (Dorchester, Poole, Weymouth, Sherborne, Wimborne Minster, Shaftesbury, Beaminster, Blandford Forum, Bournemouth, Bridport, Ferndown, Gillingham, Highcliffe, Lyme Regis, Mudeford, Sherborne, Stalbridge, Swanage, Verwood, Wareham, )
Master Locks in Durham (Durham, Sunderland, Stockton-on-Tees, Darlington, Hartlepool, Gateshead, Washington)
Master Locks in Essex (Chelmsford, Basildon, Romford, Southend, Colchester, Harlow, Brentwood, West Ham, Abridge, Billericay, Braintree, Brightlingsea, Buckhurst Hill, Burnham-on-Crouch, Canvey Island, Chafford Hundred, Chipping Ongar, Clacton-on-Sea, Coggeshall, Corringham, Dovercourt, Epping, Flitch Green, Frinton and Walton, Frinton-on-Sea, Grays, Great Clacton, Great Dunmow, Hadleigh, Halstead, Harwich, Heybridge, Hockley, Holland-on-Sea, Jaywick, Laindon, Langdon Hills, Loughton, Maldon, Manningtree, Parkeston, Rayleigh, Rochford, Saffron Walden, South Benfleet, South Woodham Ferrers, Southminster, Stanford-le-Hope, Thaxted, Waltham Abbey, Walton-on-the-Naze, West Mersea, West Thurrock, Wickford, Witham, Wivenhoe, )
Master Locks in Gloucestershire (Gloucester, Bristol, Cheltenham, Stroud, Cirencester, Tewkesbury, Berkeley, Cinderford, Coleford, Cowley, Dursley, Fairford, Innsworth, Lechlade, Longborough, Mitcheldean, Nailsworth, Newent, Northleach, Painswick, Ruardean, Stonehouse, Stow-on-the-Wold, Tetbury, Winchcombe, )
Master Locks in Hampshire (Winchester, Southampton, Portsmouth, Bournemouth, Basingstoke, Newport, Aldershot, Alton, Andover, Bordon, Eastleigh, Emsworth, Fareham, Farnborough, Fleet, Fordingbridge, Gosport, Havant, Hedge End, Lymington, New Alresford, New Milton, Odiham, Petersfield, Portchester, Ringwood, Southsea, Tadley, Waterlooville, Whitchurch, Wickham, Woolston, Yateley, )
Master Locks in Herefordshire (Hereford, Ross-on-Wye, Leominster, Ledbury, Bromyard, Kington)
Master Locks in Hertfordshire (Hertford, Watford, St. Albans, Hemel Hempstead, Stevenage, Hatfield, Apsley, Baldock, Berkhamsted, Bishop's Stortford, Borehamwood, Broxbourne, Buntingford, Bushey, Carpenders Park, Cheshunt, Chorleywood, Eastbury, Grovehill, Harpenden, Hatfield, Hemel Hempstead, Hitchin, Hoddesdon, Hunsdon, Letchworth, Moor Park, Potters Bar, Rickmansworth, Royston, Sawbridgeworth, South Oxhey, Spellbrook, Tring, Waltham Cross, Ware, Welwyn Garden City)
Master Locks in Huntingdonshire (Huntingdon, St. Ives, St. Neots, Ramsey, Yaxley)
Master Locks in Kent (Maidstone, Canterbury, Bromley, Rochester, Margate, Folkestone, Dover, Greenwich, Ashford, Broadstairs, Cranbrook, Dartford, Deal, Edenbridge, Faversham, Fordwich, Gillingham, Gravesend, Herne Bay, Lydd, Margate, Paddock Wood, Queenborough, Rainham, Ramsgate, Royal Tunbridge Wells, Sandwich, Sevenoaks, Sheerness, Sittingbourne, Snodland, Southborough, Strood, Swanley, Tenterden, Tonbridge, West Malling, Whitstable)
Master Locks in Lancashire (Lancaster, Liverpool, Manchester, Preston, Bolton, Warrington, Barrow-in-Furness, Accrington, Adlington, Bacup, Blackpool, Burnley, Carnforth, Chorley, Cleveleys, Clitheroe, Darwen, Fleetwood, Garstang, Great Harwood, Haslingden, Kirkham, Leyland, Longridge, Lytham St Annes, Morecambe, Ormskirk, Oswaldtwistle, Padiham, Penwortham, Ramsbottom, Rawtenstall, Skelmersdale, Thornton, Wesham, Whitworth, )
Master Locks in Leicestershire (Leicester, Loughborough, Hinckley, Melton Mowbray, Coalville, Lutterworth, Braunstone Town, Market Bosworth, Oadby, Shepshed, Syston, Wigston Magna)
Master Locks in Lincolnshire (Lincoln, Grimsby, Scunthorpe, Boston, Grantham, Stamford, Skegness, Louth, Alford, Bourne, Brigg, Broughton, Burgh Le Marsh, Caistor, Coningsby, Crowle, Epworth, Gainsborough, Grantham, Holbeach, Horncastle, Immingham, Long Sutton, Mablethorpe, Market Deeping, Market Rasen, North Hykeham, Spalding, Stamford, Wainfleet, Winterton)
Master Locks in Middlesex (City of London, Harrow, Enfield, Staines, Ealing, Potters Bar, Westminster )
Master Locks in Norfolk (Norwich, Great Yarmouth, King's Lynn, Dereham, Cromer, Hunstanton, Thetford, Aylsham, Cromer, Fakenham, Hunstanton, North Walsham, Sheringham, Watton, Wroxham, Wymondham)
Master Locks in Northamptonshire (Northampton, Peterborough, Corby, Kettering, Wellingborough, Corby, Daventry, Dingley, Farthingstone, Guilsborough, Hardingstone, Harpole, Kingsthorpe, Kislingbury, Maidford, Pitsford, Rushden, Silverstone, Stanwick, Upper Boddington, Yardley Hastings)
Master Locks in Northumberland (Alnwick, Newcastle-upon-Tyne, Morpeth, Hexham, Berwick-upon-Tweed, Allendale, Amble, Ashington, Bassington, Bedlington, Berwick-upon-Tweed, Blyth, Bullers Green, Corbridge, Cramlington, Haltwhistle, Morpeth, Ponteland, Rothbury, Tarset, Wooler)
Master Locks in Nottinghamshire (Nottingham, Mansfield, Worksop, Newark, Retford, Southwell, Arnold, Attenborough, Beeston, Bingham, Bracebridge, Bulwell, Carlton, Cotgrave, Eastwood, Hucknall, Kilton, Kimberley, Kirkby-in-Ashfield, Market Warsop, Netherfield, Ollerton, Southwell, Stapleford, Sutton-in-Ashfield, Toton, West Bridgford)
Master Locks in Oxfordshire (Oxford, Banbury, Witney, Bicester, Henley-on-Thames, Carterton, Thame, Abingdon-on-Thames, Burford, Carterton, Charlbury, Chipping Norton, Didcot, Faringdon, Wallingford, Wantage, Watlington, Woodstock)
Master Locks in Rutland (Oakham, Uppingham. Cottesmore)
Master Locks in Shropshire (Shrewsbury, Telford, Oswestry, Bridgnorth, Whitchurch, Market Drayton, Ludlow, Bishop's Castle, Broseley, Church Stretton, Cleobury Mortimer, Craven Arms, Dawley, Ellesmere, Madeley, Much Wenlock, Newport, Oakengates, Shifnal, Wellington, Wem, )
Master Locks in Somerset (Taunton, Bath, Weston-super-Mare, Yeovil, Bridgwater, Wells, Glastonbury, Axbridge, Clevedon, Crewkerne, Frome, Highbridge, Ilminster, Keynsham, Minehead, Nailsea, North Petherton, Norton Radstock, Portishead, Radstock, Shepton Mallet, South Petherton, Watchet, Wellington, Wincanton, )
Master Locks in Staffordshire (Stafford, Stoke-on-Trent, Wolverhampton, Walsall, Cannock, Lichfield, Biddulph, Burntwood, Cheadle, Colwich, Eccleshall, Fazeley, Fenton, Hanley, Kidsgrove, Leek, Longton, Newcastle-under-Lyme, Penkridge, Rugeley, Stone, Tamworth, Uttoxeter, )
Master Locks in Suffolk (Ipswich, Bury St. Edmunds, Lowestoft, Felixstowe, Sudbury, Haverhill, Bungay, Aldeburgh, Beccles, Brandon, Clare, Eye, Hadleigh, Halesworth, Kesgrave, Leiston, Mildenhall, Needham Market, Newmarket, Orford, Saxmundham, Southwold, Walton, Woodbridge)
Master Locks in Surrey (Guildford, Croydon, Woking, Sutton, Kingston-on-Thames, Wandsworth, Wimbledon, Brixton, Addlestone, )
Master Locks in Sussex (Chichester, Brighton, Worthing, Crawley, Hastings, Eastbourne, Bognor Regis, Horsham, Ashford, Banstead, Bellfields, Brookwood, Camberley, Caterham, Dorking, Earlswood, Egham Hythe, Englefield Green, Esher, Ewell, Farleigh, Farnham, Guildford, Haslemere, Hurst Green, Hythe End, Leatherhead, Oxted, Redhill, Shepperton, Sunbury-on-Thames, Walton-on-Thames, Weybridge, Whyteleafe, Woking)
Master Locks in Warwickshire (Warwick, Birmingham, Coventry, Nuneaton, Rugby, Solihull, Stratford-upon-Avon, Alcester, Atherstone, Bedworth, Coleshill, Henley-in-Arden, Kenilworth, Leamington Spa, Rugby, Shipston-on-Stour, Southam, Whitnash)
Master Locks in Westmorland (Appleby, Kendal, Windermere, Ambleside, Kirkby Lonsdale)
Master Locks in Wiltshire (Trowbridge, Salisbury, Swindon, Chippenham, Devizes, Marlborough, Warminster)
Master Locks in Worcestershire (Worcester, Dudley, Kidderminster, Stourbridge, Halesowen, Malvern, Evesham)
Master Locks in Yorkshire
    North Riding (Northallerton, Middlesbrough, Scarborough, Whitby)
    East Riding (Beverley, Hull, Bridlington, Driffield, Hornsea, Filey)
    West Riding (Wakefield, Leeds, Sheffield, Bradford, Halifax, Harrogate)
    York (within the Walls)

London

Master Locks in East London (Aldersbrook, Aldgate East, All Saints, Beckton, Bethnal Green, Blackhorse Road, Blackwall, Bow, Bow Church, Bow Road, Bromley by Bow, Canary Wharf, Canning Town, Chingford, Chingford Green, Chingford Hatch, Clapton, Clapton Park, Commercial Road, Cubitt Town, Custom House, Cyprus, Dalston, Dalston Junction, Devons Road, East Ham, East India, East India Dock Road , Forest Gate, Gilwell Park, Hackney, Hackney Marshes, Hackney Wick, Haggerston, Hale End, Heron Quays, Higham Hill, Highams Park, Homerton, Island Gardens, Lea Bridge, Leyton, Leyton Marshes, Leytonstone, Limehouse, Little Ilford, London Arena, Lower Clapton, Manor Park, Mile End, Mile End, Road Millwall, Mudchute, Newham, North Woolwich, Old Ford, Plaistow, Plashet, Poplar, Pudding Mill Lane, Sewardstone, Shacklewell, Shadwell, Silvertown, Snaresbrook, South Hackney, South Quay, South Woodford, Spitalfields, Stepney, Stepney Green, Stratford, Stratford Marsh, Temple Mills, Tower Hamlets, Upper Clapton, Upper Walthamstow, Upton, Upton Park, Victoria Docks, Victoria Park, Walthamstow, Walthamstow Central, Wanstead, Wanstead Park, Wapping, West Ham, West India Quay, Westferry, Whitechapel)
Master Locks in North London (Alexandra Palace, Alexandra Park, Archway, Arsenal , Balls Pond, Road Barnsbury, Bounds Green, Bowes Park, Caledonian Road, Canonbury, Colney Hatch, Cranley Gardens, Crouch End, Dartmouth Park, Drayton Park, East Barnet, East Finchley, Edmonton, Essex Road, Finchley, Finchley Central, Finsbury Park, Fortis Green, Friern Barnet, Grange Park, Haringey, Harringay, Highbury, Highbury and Islington, Highgate, Highgate Wood, Highwood Hill, Holloway, Holloway Road, Hornsey, Hornsey Lane, Hornsey Rise, Hornsey Vale, Hoxton, Islington, Kenwood House, Kingsland, Lower Edmonton, Lower Holloway, Manor House, Muswell Hill, New Southgate, Newington Green, Noel Park, North Finchley, Oakleigh Park, Oakwood, Osidge, Palmers Green, Pentonville, Seven Sisters, Seven Sisters Road, South Tottenham, Southgate, Stamford Hill, Stoke Newington, Stroud Green, Tottenham, Tottenham Hale, Totteridge, Totteridge & Whetstone, Tufnell Park, Turnpike Lane, Upper Edmonton, Upper Holloway, Waltham Forest, West Finchley, West Green, Whetstone, White Hart Lane, Winchmore Hill, Wood Green, Woodside Park)
Master Locks in South East London (Abbey Wood, Anerley, Avery Hill, Bellingham, Bermondsey, Blackheath, Blackheath Park, Borough, Bostall Woods, Brockley, Camberwell, Catford, Charlton, Crofton Park, Crystal Palace, Denmark Hill, Deptford, Deptford High Street, Docklands, Dulwich, East Dulwich, Elephant and Castle, Elmers, End Eltham, Forest Hill, Gipsy Hill, Greenwich, Grove Park, Herne Hill, Hither Green, Honor Oak, Honor Oak Park, Horniman Museum, Kennington, Kidbrooke, Ladywell, Lambeth, Lambeth North, Lee, Lee Green, Lesnes Abbey, Lewisham, London Bridge, Lower Sydenham, Mottingham, New Cross, New Cross Gate, New Eltham, New Kent Road, Newington, North Dulwich, Norwood, Norwood Junction, Nunhead, Old Kent Road, Oval, Peckham, Peckham Rye, Penge, Plumstead, Ranger's House, Riverside, Rotherhithe, Rye Lane, Shooter's Hill, South Bank, South Norwood, Southwark, Southwark Cathedral, St John's, Surrey Quays, Sydenham, Sydenham Hill, Thamesmead, Tulse Hill, Upper Norwood, Upper Sydenham, Walworth, Waterloo, Well Hall, West Dulwich, West Heath, West Norwood, Westminster Bridge , Woodside, Woolwich)
Master Locks in South West London (Balham, Barnes, Barnes Bridge, Battersea, Belgravia, Brixton, Brompton, Brompton Road, Buckingham Palace, Bushey Mead, Castlenau, Chelsea, Chelsea Embankment, Cheyne Walk, Clapham, Clapham Common, Clapham Junction, Clapham North, Clapham South, Coldharbour Lane, Colliers Wood, Copse Hill, Cottenham Park, Cromwell Road, Earl's Court, Earlsfield, East Putney, East Sheen, Fulham, Fulham Broadway, Fulham Palace Road, Furzedown, Gloucester Road, Green Park, Haydons Road, Horseferry Road, Hyde Park Corner, Kensington Gore, Knightsbridge, Lavender Hill, Loughborough Junction, Merton, Mortlake, Nine Elms, Norbury, Parsons Green, Putney, Putney Bridge, Putney Heath, Putney Vale, Queen's Gate, Queens Road, Raynes Park, Rocks Lane, Roehampton, Sands End, Sloane Square, South Kensington, South Lambeth, South Wimbledon, Southfields, St James's Park, Stockwell, Streatham, Streatham Common, Streatham Hill, Summerstown, Tooting Bec, Tooting Broadway, Tooting Graveney, Upper Tooting, Vauxhall, Vauxhall Bridge, Victoria, Wandsworth, Wandsworth Common, Wandsworth Road, Wandsworth Town, West Brompton, West Hill, Westminster, Westminster Abbey, Wimbledon, Wimbledon Common, Wimbledon Park)
Master Locks in West London (Acton, Acton Green, Acton Town, Barons Court, Bayswater, Bayswater Road, Bedford Park, Bond Street, Boston Manor, Brook Green, Chiswick, Chiswick High Road, Chiswick House, Chiswick Park, City of Westminster, Drayton Green, Ealing, Ealing Broadway, Ealing Common, East Acton, Elthorne Park, Goldhawk Road, Goodge Street, Great Portland Street, Great West Road, Gunnersbury, Hammersmith, Hammersmith & Fulham, Hanger Lane, Hanwell, High Street Kensington, Holland Park, Kensal Town, Kensington, Kensington & Chelsea, Ladbroke Grove, Lancaster Gate, Latimer Road, Maida Hill, Maida Vale, Marble Arch, Marylebone, Mayfair, North Ealing, North Kensington, Northfields, Notting Hill, Notting Hill Gate, Olympia, Oxford Circus, Oxford Street, Paddington, Park Lane, Piccadilly Circus, Queensway, Ravenscourt Park, Regent Street, Royal Oak, Shepherds Bush, Soho, South Acton, South Ealing, Stamford Brook, Tottenham Court Road, Turnham Green, Uxbridge Road, Warren Street, Warwick Avenue, Warwick Park, West Acton, West Ealing, West Kensington, West Kilburn, Westbourne Green, Westbourne Grove, Westbourne Park, Western Avenue, Westway, White City)

Wales

Master Locks in Anglesey/Sir Fon (Beaumaris, Holyhead)
Master Locks in Brecknockshire/Sir Frycheiniog (Brecon, Builth Wells, Hay-on-Wye, Talgarth)
Master Locks in Caernarfonshire/Sir Gaernarfon (Bangor, Conwy,)
Master Locks in Carmarthenshire/Sir Gaerfyrddin (Carmarthen)
Master Locks in Cardiganshire/Ceredigion (Cardigan, Aberystwyth, New Quay, Tregaron)
Master Locks in Denbighshire/Sir Ddinbych (Denbigh, Wrexham, Ruthin)
Master Locks in Flintshire/Sir Fflint (Holywell, Buckley)
Master Locks in Glamorgan/Morgannwg (Cardiff, Swansea, Barry, Caerphilly)
Master Locks in Merioneth/Meirionnydd (Barmouth, Harlech)
Master Locks in Monmouthshire/Sir Fynwy (Monmouth, Newport, Blackwood, Chepstow)
Master Locks in Montgomeryshire/Sir Drefaldwyn (Montgomery, Newtown, Welshpool)
Master Locks in Pembrokeshire/Sir Benfro (Pembroke, Milford Haven, Haverfordwest, Tenby,)
Master Locks in Radnorshire/Sir Faesyfed (Knighton, New Radnor)

Scotland

Master Locks in Aberdeenshire (Aberdeen, Peterhead)
Master Locks in Angus/Forfarshire (Forfar, Dundee, Arbroath, Brechin, Montrose)
Master Locks in Fife (Dunfermline, Cowdenbeath)
Master Locks in Lanarkshire (Glasgow, Hamilton, Motherwell)
Master Locks in Midlothian/Edinburghshire (Edinburgh)
Master Locks in Renfrewshire (Johnstone, Port Glasgow, Kilmalcolm)