How to create a DeCA: prepare, share and retain it

Creating a DeCA is not just a matter of entering data and downloading a PDF. The document must match the actual transport operation, be generated before the service starts, reach the driver in a form that can be presented on the road, and remain available to the parties that must retain it.

It is easier to manage when treated as a lifecycle with three separate stages:

1. Prepare: confirm that the service requires the control document, collect the data and generate the native PDF.
2. Share: give the driver a copy and check that the QR code opens the correct document.
3. Retain: keep the copy that belongs to each party and make it retrievable later.

If a relevant detail changes during the transport, there is a fourth step: update the document and make sure the driver receives the current version.

1. Before you begin: confirm that the service requires a control document

Spain’s administrative control document applies, subject to exemptions, to public road freight transport. Since 5 October 2026, services that fall within its scope must use the electronic format.

This should not be reduced to “every transport needs a DeCA”. The obligation depends on the service. Before preparing the document, confirm its scope, the parties involved and any applicable exemption.

For the Spanish rules and exemptions in more detail, see DeCA mandatory since 5 October 2026. The destination is currently a Spanish-language article.

2. Prepare: collect the data before generating the PDF

The first control is to identify the parties correctly:

• Contractual shipper: the party that contracts directly with the effective carrier.
• Effective carrier: the party that actually performs the transport under the relevant authorisation.

If a company subcontracts the journey to a self-employed carrier operating under their own authorisation, the relationship between the parties changes and the document must reflect that.

Next, collect the service data. Order FOM/2861/2012 sets the minimum contents. For a vehicle transport operation, the operational check will normally cover:

• the contractual shipper’s name or company name, tax identifier and address;
• the effective carrier’s name or company name and tax identifier;
• the shipment’s origin and destination;
• the nature and weight of the goods;
• the transport date;
• the registration numbers of the vehicles used;
• any observations or special authorisations that apply.

Order TRM/282/2026 allocates responsibility: the contractual shipper covers points a)–d) of Article 6 and the effective carrier covers points e)–g), together with information each party adds under point h).

3. Generate a native PDF before the service starts

The electronic DeCA must be generated from structured data. Scanning a paper form, photographing it or wrapping an image inside a PDF does not create a valid electronic document for this purpose.

Before treating the document as prepared, check that it has:

• PDF format;
• a maximum size of 5 MB;
• creation date and time in its metadata;
• modification date and time when relevant;
• a QR code inside the PDF;
• a unique, document-specific URL;
• a generation timestamp before the service starts.

The URL must use HTTPS and produce a direct PDF download. It cannot require an inspector to sign in, enter credentials, press a download button or complete another manual interaction.

4. Share: give the driver the copy before departure

Once the DeCA has been generated, the driver must receive a copy before the service starts. The copy can be:

• electronic, for example on a mobile device; or
• printed on paper.

In both cases, it must contain the QR code. The driver may also carry the QR code as a separate file.

The delivery channel can vary: email, a shared link or the operational channel agreed by the team. The important point is not the channel’s name. It is that the driver receives the correct version and can present it.

A practical access check

Before departure, test the document from a different device:

1. open or scan the QR code;
2. confirm that the URL uses HTTPS;
3. check that it downloads the PDF directly;
4. make sure the PDF belongs to the correct transport operation;
5. verify that no username, password or intermediate download button is required.

This is an operational good practice. It does not replace a content review, but it can detect broken links, the wrong document or an access flow that does not provide a direct download.

5. If the transport changes, update the version carried by the driver

A change of vehicle registration, date or another relevant detail cannot be solved by handwriting a correction on the printed copy. Handwritten notes do not count as a valid modification of the DeCA.

The Resolution of 5 June 2026 allows two methods:

1. Modify the existing PDF. Add the new data and the reason for the change. Keep the previous data visible but clearly marked as no longer valid. The URL and QR code can remain the same.
2. Generate a new PDF. The new file has a new URL and QR code, while the original must be retained to preserve the audit trail.

In both cases, the current PDF must reach the driver.

6. Retain: the link and the file are different obligations

The contractual shipper and effective carrier must retain their copies for at least one year. They may use separate repositories. If one party generated the file, it is sufficient for the other party to be able to download it during that year.

The operational download link may be disabled once seven calendar days have passed after the end of the service. That option does not remove the retention obligation.

It helps to separate two tasks:

• roadside access: the QR code and URL must work during the service;
• later filing: each party must be able to find and retain the document for the applicable period.

Fictitious example: from shipment to filing

A carrier moves two used cars from Zaragoza to Huesca. Before departure, the team confirms the parties, generates the PDF, gives the driver a copy and tests the QR code. If the tractor unit changes, it updates the document and sends the current version again. After delivery, both parties retain their copies with the service record. The example is fictitious and does not guarantee compliance for a particular document.

How Serge fits into the workflow

Serge links the DeCA to the transport information. In the current product flow, the document is generated as a native PDF with its QR code and can be shared with the shipper or carried as a mobile copy.

In Serge Freelance, a self-employed carrier saves their effective-carrier details, enters the service information and can download the complete PDF and QR image. When a detail supported by the current workflow is modified, the document remains connected to its QR.

The software helps teams prepare and retrieve the document, but people still need to review the data, confirm that the service is within scope and decide when to issue or update the DeCA. Spanish authorities do not certify or approve DeCA applications.

See how DeCA works in Serge

Self-employed carrier? You can also create a Serge Freelance account.

Final checklist

Before the service:

• I have confirmed that the transport is subject to the control document.
• The parties and shipment data are correct.
• The PDF is native, no larger than 5 MB and contains its QR code.
• The QR code downloads the correct PDF directly.
• The driver received the copy before departure.

If a detail changes:

• I updated the same PDF with an audit trail or generated a new file.
• The driver received the current version.
• The original is retained when a new file has been generated.

After the service:

• The contractual shipper and effective carrier retain their copies.
• The document can be found by transport, date or reference.
• The URL access policy is not confused with retaining the file itself.

Sources

1. Order FOM/2861/2012 of 13 December: https://www.boe.es/buscar/act.php?id=BOE-A-2013-154
2. Order TRM/282/2026 of 25 March: https://www.boe.es/eli/es/o/2026/03/25/trm282
3. Resolution of 5 June 2026 on electronic control documents: https://www.boe.es/buscar/act.php?id=BOE-A-2026-12784
4. Spanish version of this guide: https://sergelogistics.com/blog/como-hacer-deca/
5. Digital DeCA requirements: https://sergelogistics.com/blog/requisitos-deca/
6. Serge DeCA product page: https://sergelogistics.com/deca/
7. Current Serge and Serge Freelance information: https://sergelogistics.com/