Why Your Signature Gets Rejected: 5 Portal Errors Fixed

"Your signature has been rejected. Please upload a valid image."

I stared at that error message for the third time in 20 minutes. The banking portal gave me zero explanation. My signature was exactly 140x60 pixels (I triple-checked). JPG format (correct). White background (checked in Paint). File size was 18KB (well under the 20KB limit).

What was I doing wrong?

After 45 minutes of trial and error, I discovered the issue: my image was 140x59 pixels. Not 140x60. One pixel off, and the portal's validator was ruthless. No helpful error message, no hint, just rejection.

That experience taught me that portal validators are unforgiving. They don't care about "close enough." They check exact specifications, and if you're off by even one pixel, one kilobyte, or one file extension character, your application gets rejected.

This guide covers the 5 most common signature rejection errors I've seen in 8 years of helping applicants. If you've mastered the basics of signature resizing, but still facing rejections, this is your troubleshooting manual. File size errors? Our Under 20KB guide has detailed compression solutions. Need a reliable tool? Check our 7 best resizers comparison.

Error 1: Wrong Dimensions (139x60, 141x60, or Aspect Ratio Mismatch)

The Portal Says: "Image dimensions do not meet requirements" or "Invalid image size"

What Actually Happened: Your image is 139x60, 140x59, 141x60, or some variation that's not exactly 140x60 pixels.

Why This Happens

Rounding errors in image editors, aspect ratio calculations ("maintain aspect ratio" produces 140x70 instead of 140x60), or compression tools that auto-scale during export.

The Exact Fix

1. Resize to 140x60 pixels
2. Select Stretch mode (forces exact 140x60)
3. Verify: Right-click > Properties > Details > Width = 140, Height = 60

Why Stretch Works: Fit mode can produce 140x59. Stretch guarantees exact dimensions. Portals use strict validation: if (width !== 140 || height !== 60) reject.

Error 2: File Size Too Large (Over 20KB or 50KB Limit)

The Portal Says: "File size exceeds maximum limit" or "Image too large"

What Actually Happened: Your image file is 21KB when the limit is 20KB, or 52KB when limit is 50KB.

Why File Size Gets Too Large

High JPG quality (95-100% creates 25-35KB), metadata not stripped (adds 5-15KB), using PNG (20-35KB) instead of JPG (12-18KB), or complex backgrounds that compress poorly.

The Exact Fix

1. Resize to 140x60 as JPG at 80% quality
2. Use pure white background (#FFFFFF)
3. Strip metadata (resize tool does this automatically)
4. Verify: Aim for 18KB (safety buffer under 20KB limit)

If still over: Convert to grayscale (40-60% reduction) or lower quality to 75%. See detailed compression guide.

Error 3: Wrong Format (PNG Rejected, JPG Rejected, or Uppercase Extension)

The Portal Says: "Invalid file format" or "Only JPG/JPEG files accepted" or "PNG not supported"

What Actually Happened: Portal wants JPG but you uploaded PNG, or vice versa. Or your file is "signature.JPG" (uppercase) instead of "signature.jpg" (lowercase).

Why Format Matters

70% of portals accept both formats, 25% require JPG only. Some portals (Linux servers) reject uppercase ".JPG" extensions. Portals validate file content (MIME type), not just extension.

The Exact Fix

1. Resize tool > Upload image
2. Select JPG format with white background (most portals)
3. Download as signature.jpg (lowercase extension)
4. If JPG rejected, try PNG format

Extension case fix: Rename "signature.JPG" to "signature.jpg" (lowercase). Linux servers are case-sensitive.

Error 4: Aspect Ratio Distortion (Stretched or Squished Signature)

The Portal Says: "Image appears distorted" or "Signature unreadable" or just rejects without explanation

What Actually Happened: Your signature looks stretched horizontally or squished vertically because the original aspect ratio wasn't maintained properly.

Why Signatures Get Distorted

Original aspect ratio (e.g., 300x150 = 2:1) doesn't match 140x60 (2.33:1). Direct stretch creates distortion.

The Exact Fix

Use Fit mode instead of Stretch if aspect ratios don't match. Fit mode adds white padding to reach 140x60 without distortion. Only use Stretch if original ratio is close to 2.33:1.

Error 5: Transparent Background Issues (White Box Appearing on Forms)

The Portal Says: "Signature background must be white" or signature appears in a white box on the form

What Actually Happened: You uploaded a PNG with transparent background, but the portal displays it on a colored form, creating an ugly white rectangle around your signature.

Why Transparency Causes Problems

PNG transparency looks good in viewers but shows as white box on colored portal forms. JPG doesn't support transparency. Most portals require solid white background.

The Exact Fix

1. Resize your signature
2. Upload transparent PNG
3. Select JPG format with white background
4. Download and verify in Paint (solid white, not checkered pattern)

Pro Tip: Use white background JPG for 99% of portals. Safer, smaller, displays correctly on any form color.

Quick Troubleshooting Checklist

Before re-uploading your signature, verify:

Dimensions Check:

• Exactly 140 pixels wide (not 139, not 141)
• Exactly 60 pixels tall (not 59, not 61)
• Verified with Right-click > Properties > Details

File Size Check:

• Under 20KB (aim for 18KB for safety)
• If over, see compression guide

Format Check:

• JPG format (unless portal requires PNG)
• File extension is lowercase: .jpg or .jpeg (not .JPG)
• MIME type correct (use resize tool to ensure proper conversion)

Quality Check:

• Signature is readable when zoomed to 200%
• No blurry edges or excessive compression artifacts
• Background is pure white (not cream, not grey)

Background Check:

• White background (not transparent) for JPG
• Checked in Paint: solid white, no checkerboard pattern
• If PNG, confirm portal accepts transparent backgrounds

Filename Check:

• Simple name: signature.jpg (no spaces, special characters)
• Lowercase extension
• Under 50 characters total

Portal-Specific Tips

Government Job Portals (SSC, UPSC, etc.):

• Always use JPG format
• 20KB strict limit (aim for 18KB)
• Pure white background mandatory
• Save file as "signature.jpg" (lowercase)

Banking KYC Forms:

• Usually accept both JPG and PNG
• 50KB limit (more lenient)
• Can use higher quality (90%)

University Admission Forms:

• More forgiving validators
• 100KB limits common
• Still verify exact 140x60 dimensions

International Job Portals (LinkedIn, Indeed):

• Accept PNG with transparency
• Larger file size limits
• Profile picture specs different from signature specs

When All Else Fails

Use portal preview mode if available. Contact support for exact specs. Or use ImagiTool's guaranteed method: Stretch mode, JPG format, white background, 85% quality. This works for 95% of portals.

Conclusion

Portal rejection = exact specifications. Use 140x60 resize tool with Stretch mode, JPG format, white background, 80-85% quality. Verify dimensions (exactly 140x60) and file size (under 20KB) before upload. Use lowercase extension.

See our complete 140x60 guide or 7 best resizers.

Frequently Asked Questions

Why does my signature keep getting rejected when dimensions are correct?

Check file size (must be under 20KB), format (JPG vs PNG), and file extension case (signature.jpg not signature.JPG). Also verify background is pure white, not transparent. Use ImagiTool's resize tool to ensure all specifications are met simultaneously.

How do I check if my signature is exactly 140x60 pixels?

Right-click the file, select Properties > Details tab. Look for Dimensions field showing "140 x 60". Do not rely on image viewer zoom or visual inspection. Only file properties show exact pixel dimensions.

Can I use PNG format for portal signatures?

Most portals prefer JPG format. Only use PNG if portal explicitly states "PNG accepted" or "PNG required". JPG files are smaller (12-18KB) while PNG files are larger (20-35KB), increasing rejection risk for file size violations.

Why does my signature look stretched or squished?

Using Stretch mode on images with different aspect ratios causes distortion. Use Fit mode instead, which maintains signature proportions and adds white padding to reach exact 140x60. Only use Stretch if original signature aspect ratio is close to 2.33:1 (140÷60).

What if portal rejects signature for file size when I'm under 20KB?

Portal may report different file size than your computer. Aim for 18KB maximum (not 19.8KB). Strip metadata, use pure white background, save as JPG at 80% quality. Some portals round up file sizes during upload.

Should signature background be transparent or white?

Use white background JPG for 99% of portals. Transparent PNG backgrounds often display as white boxes on colored forms. Only use transparency if portal explicitly requires it or if you're certain form background is white.

How to fix uppercase extension error (.JPG rejected)?

Enable file extension visibility in Windows (View > File name extensions). Right-click file, select Rename, change "signature.JPG" to "signature.jpg" (lowercase). Linux-based portal servers are case-sensitive and may reject uppercase extensions.

Why does portal accept 140x59 but validator says wrong dimensions?

Portal's preview may display image, but validator checks exact specifications. 140x59 will be rejected during final submission even if preview works. Always verify exact 140x60 dimensions using file properties, not visual appearance.