Do you have a CSV file with named UK areas but no GSS codes? This tool could help add them. For example, if you have a column that lists "Leeds", "Birmingham", "Salford" etc, it would add a column with the local authority codes E08000035, E08000025 and E08000006 etc. This tool can recognise UK wards, Westminster parliamentary constituencies, and local authorities.
Start by using the button to load a CSV file.