CO1 · CO2 · CO3 · CO4

Home patch. Huge spread of housing age here — Victorian terraces off North Hill on five-lever mortices, and New Town builds on euro cylinders that came in at builder's-basic spec. The job's rarely the same twice.

CO2

Forces families move on a posting cycle, so lock changes between occupants are constant and always needed yesterday. Used to the paperwork.

CO3

Mostly newer estates with composite doors on multipoint gearboxes. When one won't lock it's almost never the door itself, whatever the window company told you.

CO7

Student lets around the university turn over every summer, and the quayside cottages have doors that no standard cylinder fits without measuring first.

CO6

Commuter village on the main line, so most of the work here is first thing or after six. That suits me fine.

CO6

Detached properties with long drives and outbuildings. Side gates and shed security come up more often than front doors round here.

CO5

Bungalows and older stock where the back door is still the weak point nobody's looked at since it was fitted.

CO5

Salt air eats exterior hardware, and the Strood floods on a spring tide. Both are worth knowing before you plan a callout — half the seized locks here are corrosion, not wear.

CM9 · CO5

Scattered rural properties a long way from anyone else's van. Spare keys and a second working lock earn their keep out here more than anywhere.

CO7

One road in and out, which is exactly why people here end up waiting hours for a locksmith from further afield.

CO7

Village properties with a lot of timber front doors, where a proper BS3621 mortice beats retrofitting a euro cylinder into something that was never designed for one.

CO15 · CO16

Heavy on holiday lets and HMOs, so keypad entry pays for itself in saved key handovers within a season.

CO16

Caravan parks and chalets, largely empty out of season, which makes them the obvious target and the obvious place to fit something better than a padlock.

CO13 · CO14

Older residents and older doors, and a genuine shortage of anyone who'll come out at night. I will.

CO12

Port town on shift patterns, so a two-in-the-morning callout is normal here rather than an emergency premium waiting to happen.

CO11

Listed buildings along the quay where the lock has to be sympathetic to the door as well as secure. Not every cylinder is allowed to go in one.

CO7

Constable country — a lot of listed and conservation-area properties where drilling anything is a last resort for planning reasons as much as mine.

CO6

Timber-framed and centuries old in the middle of town. Doors that have moved with the building and need easing, not replacing.

CO9

Market town with a long high street of shopfronts — hook bolts and shutter locks as often as domestic work.

CO10

Suffolk side of the border but a CO postcode, and closer to me than half of Essex is. Worth asking even though it's technically another county.

RM1 · RM2 · RM3 · RM7

First proper London stop coming down the A12, and flats above shops mean commercial and domestic work often land on the same street.

IG1 · IG2 · IG3

Dense terraces and converted flats — communal door plus individual flat locks in one visit is the normal shape of a job here.

IG11 · RM8 · RM9 · RM10

New-build blocks with access control that landlords rarely have a proper key register for. Sorting that out is usually the actual job.

E15 · E16 · E20

Tower blocks and managed developments — expect a concierge, a permit and a lift booking before anyone touches a door.

E17

Victorian terraces converted into flats, which means original timber doors carrying locks they were never cut for.

E5 · E8 · E9

Furthest I'd normally run, and only for booked or trade work. Parking is the real cost here, not the distance.