Prevent Userform Textbox From Accepting Non-Numerical Values

By Chris Newman •  Updated: 06/05/15 •  4 min read
Stop User from Entering Letters into Userform Textbox

What This VBA Code Does

You never know what your users are going to type and that’s why it is extremely vital to do as much as you can to prevent invalid inputs. In this article, I’m going to show you a couple ways to prevent your users from entering in non-numerical values (such as letter or special characters) into a Userform textbox.

Goal: To Prevent This!

Prevent Letter Inputs from Excel Userforms

INSTRUCTIONS:  Double-click your userform’s textbox inside the Visual Basic Editor and add any one of the following code snippets to the Change Event.

Allow Only Numbers (No Blanks)

Private Sub TextBox1_Change()
'PURPOSE: Prevent user from entering non-numerical values in userform textbox

Dim RemoveChar As Integer
Dim DefaultValue As Long

RemoveChar = 1
DefaultValue = 0

'Allow only numbers (no blanks)
  If Not IsNumeric(TextBox1.Value) And Len(TextBox1) <> 0 Then
    If Len(TextBox1) < 1 Then RemoveChar = 0
    TextBox1 = Left(TextBox1, Len(TextBox1) - RemoveChar)
  End If

'Change to default value if blank
  If TextBox1 = "" Then TextBox1 = DefaultValue

End Sub

Allow For Blank Values

Private Sub TextBox1_Change()
'PURPOSE: Prevent user from entering non-numerical values in userform textbox

'Allow for a blank value
  If Not IsNumeric(TextBox1.Value) And TextBox1 <> "" Then
    TextBox1 = Left(TextBox1, Len(TextBox1) - 1)
  End If

End Sub

Allow For Negative Numbers

Private Sub TextBox1_Change()
'PURPOSE: Prevent user from entering non-numerical values in userform textbox

'Allow for negative numbers
  If Not IsNumeric(TextBox1.Value) And TextBox1 <> "-" And TextBox1 <> "" Then
    TextBox1 = Left(TextBox1, Len(TextBox1) - 1)
  End If

End Sub

Using VBA Code Found On The Internet

Now that you’ve found some VBA code that could potentially solve your Excel automation problem, what do you do with it? If you don’t necessarily want to learn how to code VBA and are just looking for the fastest way to implement this code into your spreadsheet, I wrote an article (with video) that explains how to get the VBA code you’ve found running on your spreadsheet.

Getting Started Automating Excel

Are you new to VBA and not sure where to begin? Check out my quickstart guide to learning VBA. This article won’t overwhelm you with fancy coding jargon, as it provides you with a simplistic and straightforward approach to the basic things I wish I knew when trying to teach myself how to automate tasks in Excel with VBA Macros.

Also, if you haven’t checked out Excel’s latest automation feature called Power Query, I have put together a beginner’s guide for automating with Excel’s Power Query feature as well! This little-known built-in Excel feature allows you to merge and clean data automatically with little to no coding!

How Do I Modify This To Fit My Specific Needs?

Chances are this post did not give you the exact answer you were looking for. We all have different situations and it’s impossible to account for every particular need one might have. That’s why I want to share with you: My Guide to Getting the Solution to your Problems FAST! In this article, I explain the best strategies I have come up with over the years to get quick answers to complex problems in Excel, PowerPoint, VBA, you name it

I highly recommend that you check this guide out before asking me or anyone else in the comments section to solve your specific problem. I can guarantee that 9 times out of 10, one of my strategies will get you the answer(s) you are needing faster than it will take me to get back to you with a possible solution. I try my best to help everyone out, but sometimes I don’t have time to fit everyone’s questions in (there never seem to be quite enough hours in the day!).

I wish you the best of luck and I hope this tutorial gets you heading in the right direction!

Keep Learning

Chris Newman

Chris Newman

Chris is a finance professional and Excel MVP recognized by Microsoft since 2016. With his expertise, he founded TheSpreadsheetGuru blog to help fellow Excel users, where he shares his vast creative solutions & expertise. In addition, he has developed over 7 widely-used Excel Add-ins that have been embraced by individuals and companies worldwide.

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