Sign an invoice

The following diagram gives a detailed overview of the invoice signing process for post-audit countries, based on the Signing business process.

Step 1: Supplier creates the Standard Business Document

Every invoice sent to Sovos must be part of a Standard Business Document (SBD). This document includes a Standard Business Document Header (SBDH) and a Sovos Document node. To create the SBD, follow the detailed instructions in the SBDH and Sovos Document pages.

Key elements inside the SBDH:

SBDH requirementsMandatory scope informationOptional scope information

Required SBDH values:


Node	Required	Attributes	Value
StandardBusinessDocumentHeader.Sender.Identifier	Yes	Authority = An ISO 3166-1 alpha-2 country code from the country of the applicable law for the invoice.
StandardBusinessDocumentHeader.Receiver.Identifier	Yes	Authority = An ISO 3166-1 alpha-2 country code from the country of the applicable law for the invoice.
StandardBusinessDocumentHeader.DocumentIdentification.Standard	Yes		urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2
StandardBusinessDocumentHeader.DocumentIdentification.TypeVersion	Yes		2.1
StandardBusinessDocumentHeader.DocumentIdentification.Type	Yes		Attachment

Note:

Include all the mandatory nodes, as specified in the SBDH schema. If you cannot provide some information, and the respective mandatory node is not mentioned on the current page, for example the receiver.identifier, you can leave the node empty but you must still include it in the SBDH.

Add the following scope information in the SBDH:


Scope.Type	Required	Scope.Identifier
BusinessProcess	Yes	`BusinessProcess` doesn't have an Identifier node, so group it with the `BusinessService` node and set it to "Signing".
SenderDocumentId	Yes	The sender's unique document ID, used to identify the document. While the value content is not constrained, we recommend using the unique ERP document identification.
Signing.DocumentFormat	Yes	This element specifies the format of the invoice to be signed. Examples: "PDF", "XML", and "CXML".
Signing.SignatureType	Yes	Enter "Implicit", "Explicit", or "Audit".
Signing.SignatureFormat	Yes	This element specifies the signature format. Examples: "PDF", "XMLSIG", and "PKCS7".
Signing.AuditCategory	Yes (in some cases)	This element specifies the audit category. Examples: "XADESA", "PADESEPES", and "EVIDENCE".
Signing.SignFor	Yes	Enter "Sender" or "Receiver". This element specifies on behalf of which party the invoice should be signed.

Note:

For more information, see the About post-audit topic.

You can use this scope information for additional functionalities, such as including a visible signature on PDF invoices.


Scope.Type	Scope.Identifier
Signing.InitialContentEncoding	This element specifies whether the initial document — the one before Sovos has applied any signature — has any additional encoding. Currently, the only supported value is "MIME", which you can use with unsigned documents to indicate that the provided content is MIME-encoded. If the value "MIME" is used with an S/MIME-signed document, this indicates that the content was already MIME-encoded before Sovos signed it. For any other document structure, you must omit this element.
Signing.PDFSignatureOrigin	Including this generates a visible signature on the first page of the PDF. The specified coordinates determine the exact position. Example: "100,100". Note: You can only use this for PDF invoices and we recommend it only for Indian invoices.
Signing.CreateAuditDetails	If set to "true", audit details are included in the response.
AgreeementId	An identifier string that is logged and you can use to group transactions based on, for example, different pricing models. Example: "AN-123".

Below is a sample of the SBD. In addition, there's a full sample of the SBD on the Postman Samples page.

<sbd:StandardBusinessDocumentHeader>
	<sbd:HeaderVersion>1.0</sbd:HeaderVersion>
	<sbd:Sender>
		<sbd:Identifier Authority="IN"/>
		<sbd:ContactInformation>
			<sbd:Contact/>
			<sbd:EmailAddress/>
			<sbd:FaxNumber/>
			<sbd:TelephoneNumber/>
			<sbd:ContactTypeIdentifier/>
		</sbd:ContactInformation>
	</sbd:Sender>
	<sbd:Receiver>
		<sbd:Identifier Authority="IN"/>
		<sbd:ContactInformation>
			<sbd:Contact/>
			<sbd:EmailAddress/>
			<sbd:FaxNumber/>
			<sbd:TelephoneNumber/>
			<sbd:ContactTypeIdentifier/>
		</sbd:ContactInformation>
	</sbd:Receiver>
	<sbd:DocumentIdentification>
		<sbd:Standard>urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2</sbd:Standard>
		<sbd:TypeVersion>2.1</sbd:TypeVersion>
		<sbd:InstanceIdentifier/>
		<sbd:Type>Attachment</sbd:Type>
		<sbd:MultipleType>false</sbd:MultipleType>
		<sbd:CreationDateAndTime>2020-06-12T12:00:00Z</sbd:CreationDateAndTime>
	</sbd:DocumentIdentification>
	<sbd:BusinessScope>
		<sbd:Scope>
			<sbd:Type>SenderDocumentId</sbd:Type>
			<sbd:InstanceIdentifier/>
			<sbd:Identifier>123456789</sbd:Identifier>
		</sbd:Scope>
		<sbd:Scope>
			<sbd:Type>BusinessProcess</sbd:Type>
			<sbd:InstanceIdentifier/>
			<sbd:BusinessService>
				<sbd:BusinessServiceName>Signing</sbd:BusinessServiceName>
			</sbd:BusinessService>
		</sbd:Scope>
		<sbd:Scope>
			<sbd:Type>Signing.DocumentFormat</sbd:Type>
			<sbd:InstanceIdentifier/>
			<sbd:Identifier>PDF</sbd:Identifier>
		</sbd:Scope>
		<sbd:Scope>
			<sbd:Type>Signing.SignatureType</sbd:Type>
			<sbd:InstanceIdentifier/>
			<sbd:Identifier>Implicit</sbd:Identifier>
		</sbd:Scope>
		<sbd:Scope>
			<sbd:Type>Signing.SignatureFormat</sbd:Type>
			<sbd:InstanceIdentifier/>
			<sbd:Identifier>PDF</sbd:Identifier>
		</sbd:Scope>
		<sbd:Scope>
			<sbd:Type>Signing.AuditCategory</sbd:Type>
			<sbd:InstanceIdentifier/>
			<sbd:Identifier>CADESEPES</sbd:Identifier>
		</sbd:Scope>
		<sbd:Scope>
			<sbd:Type>Signing.SignFor</sbd:Type>
			<sbd:InstanceIdentifier/>
			<sbd:Identifier>Sender</sbd:Identifier>
		</sbd:Scope>
	</sbd:BusinessScope>
</sbd:StandardBusinessDocumentHeader>

Sovos Document requirements:


Node	Required	Attributes	Value
SovosDocument.SovosLegalDocument.Base64Document.EmbeddedDocument (with child nodes)	Yes	id Always enter "1" filename The name of the file mimeCode The mime type of the Base64-encoded invoice, as specified by the Internet Assigned Numbers Authority (IANA)	The string of the Base64-encoded invoice

Here is a Sovos Document sample:

<svs:SovosDocument>
 <svs:SovosLegalDocument>
  <enc:Base64Document>
   <enc:EmbeddedDocument id="1" filename="invoice.pdf" mimeCode="application/pdf">*Base64 encoded file*</enc:EmbeddedDocument>
  </enc:Base64Document>
 </svs:SovosLegalDocument>
</svs:SovosDocument>

Step 2: Supplier sends the SBD to Sovos

The supplier sends a POST request to the /documents endpoint.

To use this endpoint, configure these request body parameters:


Name	Type	Required	Description
data	string	Yes	The SBD encoded in Base64, as created in step 1
dataEncoding	string	Yes	Always enter "base64"

Request sample

curl --location --request POST 'https://api-test-tls.sovos.com/v1/documents' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer TOKEN' \
--header 'x-correlationId: SET-TO-UNIQUE-VALUE' \
--data-raw '{
	"data": "PD9...d4=",
	"dataEncoding" : "base64"
}'

Response sample

{
    "success": true,
    "status": 200,
    "message": "Process Completed",
    "timestamp": 1605183801553,
    "data": "PEF...lPg=="
}

Step 3: Sovos signs the invoice

Sovos signs the invoice by applying the specified signature to the invoice.

Step 4: Sovos returns the signed invoice

As a response to the request, Indirect Tax API returns a JSON response message with an HTTP status code of 200 (synchronous transaction) and an application response that includes the signed invoice and, optionally, the audit details. See step 2 for a response sample.

Step 5: Supplier sends the invoice to the buyer

After receiving the signed invoice, the supplier should send the invoice to the buyer using the agreed-upon channel. This process is out of Sovos' scope.

Step 6: Archiving

As an optional step, the supplier can store the signed invoice in the compliant archive with Sovos. For more information, see the eArchiving page.

Sovos Docs