Postcode finder in Excel: How to match Postcodes with addresses?

Key takeaways

• Excel requires reference data to match addresses with postcodes automatically.

• VLOOKUP/XLOOKUP with city-state combinations prevents incorrect postcode matches across states.

• Custom VBA functions handle complex matching when standard Excel formulas aren’t sufficient.

• Regular database updates and clean address formatting ensure accurate postcode lookups.

Introduction

If you have stared at a spreadsheet full of addresses missing postcodes and suffered from a headache, you’re not alone. Whether you’re cleaning mailing lists, organizing customer data, or planning logistics routes, finding missing postcodes is one of those tedious tasks that can eat up hours of your day.

But we have good news for you: Excel has several handy tools to help you fill in those blanks efficiently. From simple lookup functions to built-in geography features, there are ways to automate this process and save yourself from spending hours manually inputting data.

In this article, we will explore these methods and best practices together to find postcodes in Excel.

💡 GeoPostcodes maintains the world’s most comprehensive postcode database, sourced from over 1,500 trusted sources, and always up-to-date. Get accurate, geocoded postal data that integrates seamlessly with Excel for professional-grade address validation and mapping solutions. Browse GeoPostcodes databases and download a free sample.

Understanding the Problem: Why Excel Alone Can’t Guess postcodes

Here’s the thing—Excel is mighty, but it’s not a mind reader. It can’t magically determine the postcode that belongs to “123 Main Street, Springfield” without some reference data to work with.

Think about it: there are multiple Springfields across the United States, each with different postcodes. Without additional context, Excel has no way to determine which Springfield you’re referring to.

This is why having a reliable postcode database is crucial for any lookup operation. Excel needs that reference table to match your addresses against known postcode data.

Preparing Your Data in Excel

Before diving into lookup formulas, organization is key. Structure your address data with separate columns for Street Address, City, State, and eventually, your postcode column, where results will appear.

It’s best to work with clean data. Remove extra spaces, standardize abbreviations (such as “St.” vs. “Street”), and ensure consistent formatting across all your address fields.

All prepared? Let’s start with some step-by-step guidelines.

Method 1: Using VLOOKUP or XLOOKUP with a postcode Database

This is the workhorse method that most Excel users rely on. VLOOKUP and XLOOKUP serve as a powerful bridge between different data columns, enabling you to search for specific values and retrieve corresponding information from adjacent fields. This is particularly useful when working with structured location data, where postcodes are available in one column and addresses or localities are available in another.

This is how you do it:

1. First, you’ll need to download or import a postcode database, which is readily available as CSV files or Excel spreadsheets from various sources online. For example, GeoPostcodes offers a free sample postcode dataset for more than 100 countries.
2. Set up your lookup table with columns for City, State, and postcode.
3. Use a formula like =XLOOKUP([@City]&[@State], postcodeDB[City]&postcodeDB[State], postcodeDB[postcode]) to find matches based on your address components. Important: The function takes three arguments separated by commas: first, the columns containing the city and state values for which you want to find a postcode, then the columns where the search will take place, which are the equivalent city and state columns in the lookup table and finally the column containing the postcodes.

The key is an interconnected city and state for more precise matching. This prevents Excel from returning the wrong postcode when multiple towns share the same name across different states.

However, there can be cases in which a city may have more than one postcode; then XLOOKUP will only return the first match. We can work around this by using the FILTER function instead:

1. Same as before, we set up a lookup table containing cities, states, and postcodes, and we call it “postcodeDB”.
2. We use the FILTER alongside TEXTJOIN for formatting so we get a full listing of postcodes:
   =TEXTJOIN(", ", TRUE, FILTER(postcodeDB[postcode], (postcodeDB[City]=%VALUE%)*(postcodeDB[State]=%VALUE%), "")), replacing %VALUE% with the cells containing the city and state we want to search for.
   Thanks to TEXTJOIN, the result will be in one cell, separated by commas.

Method 2: Custom VBA or User-Defined Functions (UDFs)

When standard formulas aren’t cutting it, VBA or UDF functions can handle more complex matching logic. This approach is perfect when you need to account for partial matches, multiple postcodes per city, or special formatting requirements.

You can create a custom function that searches through your postcode database using more advanced criteria than simple exact matches. However, this method requires some programming knowledge and may not be suitable for all users.

Here’s a basic UDF example:

**Function Findpostcode(City As String, State As String) As String
    ' Retrieve a matching postcode given a city, state
   
   Dim i As Long
    
    ' Loop through rows starting from row 2 (assuming row 1 has headers)
    For i = 2 To 1000 ' Search up to row 1000
        If Cells(i, 1).Value = City And Cells(i, 2).Value = State Then
            Findpostcode = Cells(i, 3).Value
            Exit Function
        End If
    Next i
    
    ' postcode not found
    Findpostcode = "postcode not found"
    
End Function**

The function searches your database and returns matching postcodes. It assumes three columns: City, State, and postcode, and has a search limit set to 1000 rows, but can be modified to best suit the needs of your dataset.

To implement it, press Alt+F11 to open the VBA editor, insert the code in a new module, and then use =Findpostcode(A2, B2) in your worksheet cells.

Troubleshooting Common Issues

You may see multiple postcodes listed for a single city, particularly in larger metropolitan areas. The solution is to either use additional address components, like street names, for more precise matching or manually verify these results.

Incomplete addresses pose another challenge. When you’re missing state information, consider using the most populous city with that name or flag these entries for manual review.

Getting the Most out of Excel’s Built-in Geography Data Type

Excel’s Geography data type is a newer feature that can automatically recognize and convert location data. Select your address data, go to the Data tab, and click “Geography” to convert recognized locations.

It is essential to note that this feature has some limitations; by default, it does not recognize postcodes, and it cannot consistently retrieve data results for all locations. However, it is perfect to work alongside an existing location dataset, for example, US postcodes. You can, for example, retrieve the City, state, and postcode combinations using the tools described above and extend this data by transforming the result into the special Geography data type to pull structured geographic information directly into your worksheet.

Best Practices for Maintaining Your postcode Lookup in Excel

• Keep your postcode database up-to-date. postcodes change more frequently due to urban expansion and postal service optimizations.
• Set up a regular update schedule, monthly or even weekly, to refresh your reference data.
• Document your formulas and create clear instructions for your team to use. This prevents confusion and ensures consistency across your organization.

Conclusion

Finding postcodes in Excel doesn’t have to be a manual nightmare. Whether you choose VLOOKUP functions, custom VBA solutions, or Excel’s built-in geography features, the key is having reliable reference data and clean, well-organized address information.

GeoPostcodes provides the world’s most comprehensive postcode database, covering 247 countries, and sourced from 1,500 authoritative providers. Our highly accurate, geocoded data transforms Excel spreadsheets into powerful tools for location intelligence, supporting global business operations. Browse our databases for free or request a quote here.

FAQ