Fix "Send Envelope Failed" Error in Digital Signing


After successfully building a tenancy agreement and trying to send the document for digital signing, the submitting to signing fails, and you see the message "send envelope failed".


The most likely reason for seeing this error is that one of the attachments isn't readable by Signable (the third-party digital signing service we use).

Signable does not support editable PDFs, also known as form-field PDFs. This is due to these types of PDFs being live and interactive documents that do not need to be downloaded to be edited in any way.

Because of this, the system will either not allow the PDF to be processed or will wipe all information added to this PDF.

You must 'flatten' these PDFs before building the agreement so that your information stays on your document and processes just fine.

It's also possible that the third-party service is experiencing difficulties, but please try the fix below first.


To fix the issue, please follow these steps.

1. Flatten the attachment PDFs

First, you'll need to flatten the PDFs to remove any editable fields. The issue is unlikely with the EPC, as that doesn't typically have editable fields. If you used the EPC number method for adding the EPC, you would not need to flatten the EPC.

The most likely document will be the electrical report because electricians often use an editable PDF to fill in the test details. They should send the document flattened, but sometimes they don't. Try the gas safety record if it fails after the flattened electrical report.

The instructions for flattening a PDF below can also be found on this help page, including screenshots:

Flatten a PDF on Windows

Open up your PDF document. Once open, click 'File', then 'Print'. You're then going to click on the drop-down on 'Printer' and select 'Microsoft Print to PDF', then click the 'Print' button.

You'll then be prompted to save your document. Save it as something memorable, as this will be your new document to upload. Once given a name, click 'Save'. Your document's information has now been flattened and will be uploaded onto Digital Signing without issues.

Flatten a PDF document on Mac.

Open your 'Finder', right-click on your document, hover your mouse over 'Open With', and click 'Preview'.

Once here, click on the drop-down at the bottom, select 'Save as PDF', then click 'Print'.

You should then be directed to a page to save this file rather than print it. Give it a memorable title and click 'Save'.

This document has now been flattened and will keep all information in place and will now process into digital signing successfully.

Online tools

You can find PDF flattening tools online if the above guides don't work.

2. Duplicate or edit the agreement

From the tenancies list, if 'edit' is available from the actions button, click edit. Otherwise, click duplicate to create a new agreement and then click edit on the duplicated agreement.

3. Replace the uploaded attachment

Go to the document upload page (usually page 5), remove the old attachment, and replace it with the flattened one.

4. Save and Build

Click next to the last page and click Save and Build. Wait for the document to be completed.

5. Submit for digital signing

From the actions button, click digital signing, and it should now work.

If it fails, repeat the flattening process with all uploaded attachments and try again.

If you still experience trouble, please check our status page to see if there are known issues; if not, please submit a support ticket.