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File Restrictions

Supported file types

SureSign accepts common document and image formats for general uploads, including PDF, Word (DOC/DOCX), Excel (XLS/XLSX/CSV), plain text, and standard image formats (JPG, PNG, WEBP). Document templates (used by Admins) are restricted to Word and PDF formats.

Maximum file size

Your organisation's administrator sets the maximum upload size (50MB by default). If your file is larger, the upload will be rejected.

Why a file might be rejected

SureSign checks every upload for a supported and safe file before storing it. A file may be rejected if:

  • Its type is not supported.
  • Its contents do not actually match its file extension.
  • Its file name looks unsafe (for example, it contains characters used to try to escape the intended folder).
  • It is a Word or Excel file that looks like it could overwhelm the system when opened (an oversized or unusually compressed file).

In every case, SureSign shows a short, generic message (for example "This file type is not supported.") rather than technical detail, and nothing is stored.

What to do if your file is rejected

  • Confirm the file is genuinely the type it claims to be (for example, a .pdf file that is really a renamed image will be rejected).
  • Try re-saving or re-exporting the file from its original application.
  • If you believe a legitimate file is being rejected, contact your Super Admin.