One postcode, four levels: YO18 7TG

Read a postcode from left to right and each level narrows the location. YO is the postcode area; YO18 is the district; YO18 7 is the sector; YO18 7TG is the full postcode, also called a postcode unit. Each longer code includes the part before it. The district is YO18, not just 18, and the sector is YO18 7, not just 7.

Keep the beginning each time: YO → YO18 → YO18 7 → YO18 7TG. The bold part is the complete code for that level.

See the difference on the map

The coloured pieces below are the shapes you can click to build territories. On an area map, one click can colour the whole YO area. On a district map, YO18 can have a different colour from neighbouring YO17 or YO62. On a sector map, YO18 7 and YO18 8 can be coloured separately. The district and sector pictures use the same view and zoom: the extra boundaries come from the map detail, not from zooming in.

Same place, more choices. The two lower pictures cover exactly the same extent. Sectors add smaller colourable pieces inside the district.

Choose the smallest shape you need to colour

Think of a real boundary between two of your territories. Would one person look after all of YO, or would different people cover parts of it? If a boundary needs to run between two districts, choose district detail. If it needs to run inside a district, choose sectors. You can always combine several shapes into one territory; you cannot divide a single postcode polygon into finer postcode shapes on a coarser map.

Postcodes do not all have the same number of letters

The part before the space is the outward code: it identifies the district. The three characters after the space are the inward code. Its first character is a number, which adds the sector; its final two letters complete the full postcode. The area starts with one or two letters, while a district can have one or two numbers and sometimes an extra letter. SW1A is a district, for example: the A belongs with SW1A. Do not split every postcode after a fixed number of characters.

A small space makes a big difference

YO18 is a district. YO1 8 is a sector in the different district YO1. They are not the same place. Write sectors with a space before the final digit, and full postcodes with a space before the final three characters. Some compact map labels omit the space: YO187 on a sector map means YO18 7. These illustrations put it back to make the levels easier to recognise. Use clearly spaced codes in your own spreadsheets.

Zoom, visible boundaries and colouring mode are different

Zooming enlarges the shapes already on your map; it does not turn an area map into a district or sector map. A detailed map can show broader boundaries for reference as well as its smaller shapes. Use the Colour selector at the top of the editor to check which level a click will colour. In START HERE, select the zone in the legend first, then click the map shapes you want to give that zone’s colour. If you have already coloured smaller shapes, colouring their whole parent area can replace that work; read the warning before continuing.

See how the Colour selector works → Build your first territory →

A full postcode is not necessarily one house

A full postcode usually refers to a group of delivery addresses; some large users have a postcode of their own. It is not a precise building boundary. The three polygon map choices discussed here are areas, districts and sectors, with sectors giving the finest of those boundaries. A postcode dot or marker is a location placed on the map, rather than another colourable polygon. If you want to show customers or branches, you may be able to use dots on a simpler map without needing sector boundaries.

Postcode boundaries are not county boundaries

Postal geography is a different system from counties, councils and wards. A postcode area may cross administrative boundaries, and its name does not mean it covers only the town or county you associate with it. Choose postcode maps when postcodes are how you allocate work or record customers. If your report genuinely needs county boundaries, look at the county map instead. Also, a large rural polygon is not necessarily a bigger market than a small urban one: size on the page does not tell you its population or sales.

Detailed customer data can still work on a simpler map

Choose the map detail for the territories you want to see and edit, rather than the length of the postcodes in your file. For example, a sales dataset recorded by sector can be added together for its parent districts or areas. Full-postcode values can also contribute to those totals. In My datasets, upload the CSV, check the postcode and value columns, then name and save it. Data must match the supported postcode geography; check the import results and any partial-total warning. Going the other way is different: a total for YO18 does not tell us how much belongs in YO18 7 or YO18 8, so the tool cannot invent that split.

Upload your own figures → Import a list to colour territories →

Your territories do not have to stop at a postcode area

A territory is the collection of shapes you give the same zone colour. On a district map you might group several YO districts with neighbouring districts in another postcode area. They remain separate postcode shapes, but their colour and legend entry show that they belong to the same team. Add your own zone names in the legend, and use Hide unassigned areas when you want the finished map to focus on the places you have coloured. More detail is useful only when you need those extra divisions; it can also mean more labels to fit on a printed page.

Try your own patch before choosing a licence

Find a place you know and try colouring the territories you actually need. Check the Colour selector, the available boundaries and how the labels look in Print View. If your job depends on an import, try a small representative sample too. An area map is often enough for a broad national overview; districts suit many regional territory plans; sectors let you make finer local divisions. Check the selected map’s current unlock options for what the licence includes before buying. The map links in the public handbook open a preview of the editor, not a payment.

Find the map choices in the tool → Read about licences and unlocking →

Check a postcode you are unsure about

Postcodes can be introduced, changed or retired, so an old customer list may contain codes that do not match a current map. Check questionable entries before treating an unmatched row as zero sales or no customers. The pictures here use the tool’s real map artwork with example colours and larger labels for explanation. They explain the levels; they are not a postcode lookup or a statement that a particular address is current.