Four separate authorities appear against SL4, which is a lot for a single outcode and is the first thing worth getting straight if an order is going to an address inside it. The post town is Windsor, and the ground covered runs from the built-up town out through riverside parishes and into open country.
What SL4 actually covers
The core of the outcode is Windsor itself and the quarters that belong to it — Clewer, Dedworth, Spital and Cranbourne all appear in the coverage, along with the wards Clewer & Dedworth East and Clewer & Dedworth West. Terraces and short streets around the middle sit close together, with doors opening onto the pavement in the older parts, while the Dedworth ground reads as a more open estate pattern with gardens and drives.
Immediately alongside sit three more places that most people think of as separate addresses but which share the same outcode here: Old Windsor, Eton and Eton Wick. Old Windsor and Eton are both named as parishes in the SL4 list, which tells you they are treated as distinct communities rather than as suburbs.
Further out the outcode loosens into something much more rural. Water Oakley, Oakley Green, Woodside, Boveney, Dorney, Winkfield and Fifield (east) are all named in the coverage, and the parish list adds Bray and Sunninghill and Ascot. These are hamlet and village addresses, spread thinly over ground that is mostly fields and lanes, and they are held inside SL4 by history and by the postal boundary rather than by any continuous built-up edge.
That is why the authority line names four councils — Windsor and Maidenhead, Bracknell Forest, Buckinghamshire and Slough — and why the ward list includes places as far apart in character as Bray, Ascot & Sunninghill, Burnham and Cippenham Village. One outcode, four authorities. It is unusual, and it is real.
Why a doorstep drop works against you in SL4
The first difficulty is the spread. A round covering SL4 can run from a terraced street in the town to a hamlet address fifteen minutes away down a lane, and the only thing the two have in common is the postcode. That does not make a doorstep model impossible, but it does make the arrival times hard to predict and the day's route long.
The second is the frontage. Near the middle of the town, a door onto the pavement leaves nothing between a parcel and the street. Out among the lanes, a house behind a hedge or set back from the verge is invisible from the road, and a driver has nowhere safe to leave a vehicle while they work out where number whatever actually is.
The third is the ordinary working week, which applies everywhere in the outcode without exception. Most addresses here have nobody in during the day, so a delivery that requires an answer at the door requires the one thing that is reliably missing.
The locker that works for SL4
The collection point settles all of that by removing the door from the process entirely. You pick the point at checkout, the ones offered are generated from the postcode you entered, and the address itself decides whether you are matched to a cabinet near the town or one closer to the village end. Four authorities, one list.
For most SL4 addresses there is a real choice of points. The right one is the cabinet you pass in the course of a normal week rather than the nearest one on a map, because a collection you can fold into an existing journey is one you will actually make. The parcel waits in its compartment, the code lands on your phone, and the collection happens when it suits you rather than when a van happens to be in the area.
If your address sits anywhere near the edge of a served zone, which many SL4 addresses do, enter the full postcode and check the returned list before you pay. It takes a moment and it prevents a surprise.
Where the week goes for an SL4 order
An SL4 order is dispatched within a day of being placed, Monday to Saturday, and from there it moves through the InPost locker network rather than being driven to a door. Tracking accompanies it from dispatch onwards.
Your chosen cabinet is normally where it ends up, two to three working days after it was dispatched. The hold on a parcel that has arrived is seventy-two hours, and within that window you can collect at any point you like using the code you were issued.
If the cabinet you selected is one you only visit once a week, the window is worth a second thought before you pay, particularly for village addresses where the alternatives may be some distance apart. A short delay in choosing is better than a long detour later.
Delivery costs five pounds per order whatever the order holds, there is no minimum basket, and nothing else is added at the checkout.
SL4 questions we actually get
Eton, Old Windsor and Bray are separate parishes inside SL4 — do I collect from the one I live in?
Not necessarily, and the parish is not what decides it. All three are named as parishes inside this outcode, but the collection points for an address are produced from its postcode, and that can mean a point in a different parish from your own. If your postcode returns several options, pick on convenience; if it returns one, that one serves the address whichever parish name it carries.
Why does a Cippenham Village address carry a Windsor postcode?
Because Cippenham Village appears among the wards attached to SL4, and the authority for that ward is Slough even though the post town on the address is Windsor. Post towns, wards and authorities are three different things drawn by three different sets of rules, and they do not have to agree. None of it changes the cost of an order or how long it takes to reach the cabinet you chose.
For everything that happens before the parcel moves — the ordering steps, the age check and payment from the wallet — start with the Slough ordering guide, and the Slough delivery and locker collection guide picks it up from there.
