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# rules restrictions opentrust

## Rules and Restrictions for OpenTrust Envelopes

The eSignature API enforces certain rules and restrictions when at least one signer or in person signer is required to use an OpenTrust signer certificate (RequireSignerCertificate=OpenTrust).

The following restrictions apply when sending an envelope:

* Sign on Paper, Document Markup, Field Markup, watermarks, and Electronic Notary cannot be enabled for the envelope.
* A SMS Authentication or Access Code authentication check must be included for the OpenTrust signer.
* All recipients must be the only recipient in their routing order.
* The OpenTrust signer must have at least one required Signature or Initials tag in the envelope (the envelope cannot be sent for Free-Form signing). Additionally, the signer cannot have more than 5 OpenTrust Signature tabs in the envelope.
* When a signer in the envelope is required to apply a digital signature, then all subsequent signers that have Signature or Initial tags are required to use a digital signature. Note that other recipient types can be used and subsequent signers can use other tab types.
* Downloading documents individually or as a combined PDF is allowed. However, downloading the combined PDF of all documents might cause the digital signatures to appear invalid due to the process of combining the documents. This is a known issue and each document can be downloaded individually to verify the digital signature.

Other restrictions that apply to envelopes:

* Envelopes cannot be corrected if at least one OpenTrust signer has signed the envelope.