Spanish Immediate Supply of Information (SII)
Under the SII, taxpayers are required to submit certain reports to the Spanish tax authorities within four working days. Certain other reports are required to be submitted on an annual basis. The reports are unique to Spain and contain a large number of optional and conditional fields, with further validations performed by the tax authorities upon receipt.
The process for SII reporting and submission is as follows in ONESOURCE:
- Import Data
- Review Warnings
- Run Reports
- Submit E-file Reports
The following graphic shows a high level process flow:

Import Data
The first step to preparing for SII is importing the data into ONESOURCE using the appropriate import and allocation specifications. This step is configured by your implementation team and additional automatic import via SFTP may be configured.
To import data:
- InTransactions > New Import, selectTransactionsfor Import type.
- Select the allocation and import specification, as appropriate. The imported data goes to SII reports and the Spanish VAT Return.

Review Warnings
For standard transactions, ONESOURCE validates the data during import and highlights areas where data does not match expectations or requirements.
ONESOURCE Indirect Tax Compliance will provide warnings on import of data. These warnings are based on the validations and checks the Spanish tax authorities run on submission. The warnings provide you with the opportunity to ensure the data that will be uploaded will not incur validation errors when submitted.
You can select
Import details > Warnings
to view warnings. On the Warnings screen, transactions can be edited to correct the information. For example, if a transaction doesn't have an invoice date, the ‘Invoice date is missing’ warning is displayed. Users can edit the transactions to clear warnings before submitting the data to tax authorities.
SII Upload Validations
After transactions are edited, you can complete a final review of the XML (if you want) before submission to tax authorities. To complete a final review:
- SelectReports > Digital Tax Reporting.
- Select the relevant report (for example, SII Invoices Issued).
- Enter the parameters then selectXMLas output. The report can also be viewed on screen or exported to Excel as an initial step prior to this.

The XML is available for download from
Reports > Output
. If the XML failed any of the validations (validations are as per the Spanish tax authority), the Business Validations
column displays a number that is a hyperlink for the relevant XML. As shown in the following graphic, clicking the number hyperlink shows the failed validations.
Header Information
If any of the mandatory fields in the XML header are missing in the data that is submitted (for example, the Reporting Period or Tax Filer NIF), then the entire submission fails because AEAT will not accept the XML.
ONESOURCE Indirect Tax Compliance captures the response from AEAT and displays it on the Submission screen. The Submission screen includes the Submission Failed status. The relevant error message (with the line number and column number details) are included in the
Error Description
column.Invoice Information
Invoice-level errors are another form of errors. If the submission is accepted by AEAT, then the invoice-level checks are completed and the response from the AEAT is provided per invoice. Errors (such as Duplicate invoice, or Reporting year is blank) have an Invoice. Errors status and include a hyperlink. Selecting the hyperlink displays all the relevant invoice errors returned by AEAT for the submission.
To view the error details, you can select the InvoiceErrors hyperlink in the
Status
column on the Submissions screen ( Reports
> Submissions
), or you can run the respective error reports (for example, SII Invoices Issued Error/SSI Invoices Received Error). Running the respective error report is useful if you want to review the a number of submissions.
You make the changes (or edits) as needed to clear the invoice errors then generate the report to submit corrected data to the authorities again (or, if the setting is enabled, to leave the invoices to be automatically uploaded). Editing invoices changes the status to TOBEUPLOADED, which means that any edited transactions are automatically included in the next scheduled upload to AEAT.
Upload Status
The system has 2 types of statuses for SII transactions:
- TOBEUPLOADED
- UPLOADED
All transactions have a TOBEUPLOADED status when initially imported. Only invoices with a TOBEUPLOADED status are included for submission to tax authorities. After an invoice is successfully submitted, its status is updated to UPLOADED.

Transactions that failed during upload or that were edited since the upload have a TOBEUPLOADED status.

So there is no chance of duplicate data submissions, each submission includes only the transactions with an upload status of TOBEUPLOADED (and not all the transactions for an entity and period) are sent to AEAT.
Run Reports
You can find the SII reports by clicking
Reports > Digital Tax Reporting
.To run a report, select the following required parameters:
- Choose theEntityand time period, as required.
- Set theCommunication Typebased on the type of transactions that must be submitted to tax authorities. For example, A0-New invoices or A1/A4-corrective invoices.
Create XML Reports
Although the standard screen and Excel reports are available, you will need to download the data in .XML format for SII reports. Spain tax authorities accept SII reports in .XML format only.
After transactions are edited, you can complete a final review of the XML before submission to the tax authorities.
To complete a final review:
- Go toReports > Digital Tax Reporting.
- Select the relevant report (for example, SII Invoices Issued).
- Enter the parameters then select XML as the output. As an initial step prior to this, you can choose whether you want to view the report on screen or export it to Excel.
- The XML is available for download fromReports > Output. If the XML failed any validations (validations are as per the Spanish tax authority), a hyperlinked number for the relevant XML displays in theBusiness Validationscolumn. Selecting the hyperlinked number shows the failed validations.
Submit E-file Reports
For Spain, automatic E-filing is mandatory. You can trigger automatic E-filing from the onscreen report using the
E-file
option, or you can set the system to submit reports automatically, at regular intervals, using the automatic filing frequency option. The automatic filing frequency option is configured by the implementation team and set to the interval period requested by the customer. note
Manual filing isn't applicable for Spain.