diff --git a/etl/README.md b/etl/README.md
index bdb043ba..37db7f61 100644
--- a/etl/README.md
+++ b/etl/README.md
@@ -11,7 +11,9 @@ The scripts in this directory are used to extract, transform and load (ETL) the
 
 # :arrow_down: Downloading Ordnance Survey data
 
-The building geometries are sourced from Ordnance Survey (OS) MasterMap (Topography Layer). To get the required datasets, you'll need to complete the following steps:
+The building geometries are sourced from Ordnance Survey (OS) MasterMap (Topography Layer). We also make use of OS Open TOID data which proves access to a generalised location for those geometries.
+
+## Downloading MasterMap data
 
 1. Sign up for the Ordnance Survey [Data Exploration License](https://www.ordnancesurvey.co.uk/business-government/licensing-agreements/data-exploration-sign-up). You should receive an e-mail with a link to log in to the platform (this could take  up to a week).
 2. Navigate to https://orders.ordnancesurvey.co.uk/orders and click the button for: ✏️ Order. From here you should be able to click another button to add a product.
@@ -23,6 +25,15 @@ The building geometries are sourced from Ordnance Survey (OS) MasterMap (Topogra
 4. You should be then able to check out your basket and download the files. Note: there may be multiple `.zip` files to download for MasterMap due to the size of the dataset.
 6. Unzip the MasterMap `.zip` files and move all the `.gz` files from each to a single folder in a convenient location. We will use this folder in later steps.
 
+## Downloading OS Open TOID data
+
+1. Navigate to the download page at https://osdatahub.os.uk/downloads/open/OpenTOID
+2. Select the area of the map you require location data for (e.g. the squares covering London) and download the data in CSV format:
+
+![](screenshot/OpenTOID.png)
+
+3. Unzip the `.zip` file(s) to get the CSV files and move them to a single folder in a convenient location. We will use this folder in later steps.
+
 # :penguin: Making data available to Ubuntu
 
 Before creating or updating a Colouring London database, you'll need to make sure the downloaded OS files are available to the Ubuntu machine where the database is hosted. If you are using Virtualbox, you could host share folder(s) containing the OS files with the VM (e.g. [see these instructions for Mac](https://medium.com/macoclock/share-folder-between-macos-and-ubuntu-4ce84fb5c1ad)).
diff --git a/etl/screenshot/OpenTOID.png b/etl/screenshot/OpenTOID.png
new file mode 100644
index 00000000..d550be79
Binary files /dev/null and b/etl/screenshot/OpenTOID.png differ