How to Concatenate a String with a Number in Power Automate

While building flows in Power Automate, you may need to combine text values with numbers to create unique identifiers, email subjects, file names, invoice numbers, or custom messages.

Power Automate provides the concat() expression that makes it easy to join strings and numeric values into a single output.

Why Concatenate Strings and Numbers?

Create order numbers
Generate invoice references
Build custom email subjects
Create unique file names
Format user-friendly messages

Using concat() Expression

The concat() function combines multiple values into a single string.

concat('Order-',1001)

Output:

Order-1001

Using Dynamic Content

You can combine static text with dynamic numeric values retrieved from SharePoint, Dataverse, Excel, or other connectors.

concat(
'Invoice-',
outputs('Get_Row')?['body/InvoiceNumber']
)

Creating Email Subjects

A common use case is generating dynamic email subjects.

concat(
'Order Confirmation #',
variables('OrderID')
)

Example Output:

Order Confirmation #1025

Creating File Names

Concatenation is frequently used when creating unique file names.

concat(
'Report_',
variables('ReportID'),
'.pdf'
)

Example Output:

Report_5001.pdf Important: The concat() function automatically converts numbers into text values, so explicit string conversion is usually unnecessary.

Common Use Cases

Invoice numbers
Order references
Email subjects
Document naming
Customer identifiers
Notification messages

Best Practices

Use meaningful prefixes and suffixes.
Keep naming conventions consistent.
Use dynamic content whenever possible.
Test output formats before deployment.
Document complex expressions.

Key Takeaways

concat() is the primary function used for string concatenation.
Numbers can be combined directly with text values.
Dynamic content works seamlessly with concat().
Useful for file names, email subjects, and identifiers.
Improves automation flexibility and readability.