How to generate your DeCA for free, step by step: the complete guide to filling in the electronic control document without fighting the software

It is written to be read once and then never needed again: what to put on the desk before you start, what each screen asks you and why, what happens when you press Send, what you show the officer if you get stopped, and how to fix a mistake without drama. If you would rather have the quick reference, field by field, it is on the tool's own help page. This is the version that walks you through it.

Five minutes with the data in front of you, three emails that send themselves and a QR code the officer scans at the roadside. Generating the DeCA takes no computer skills. It takes knowing your trade, and you already do.

Before you start: put this data on the desk

The form takes about five minutes if you do not have to get up and look for anything. Have this ready:

• Your company (the actual carrier, transportista efectivo): name, NIF and an email address. The document and the link for correcting it both go to that address.
• Your customer (the contractual shipper, cargador contractual, whoever hired you for this job): name, NIF, address and email. If the job comes from another transport company, an agency or a freight forwarder, that company is the customer, not the final owner of the goods.
• The job: start date and time, and your internal reference if you use one.
• Driver and vehicle: full name, email address, the tractor unit registration and, if you are running an articulated combination, the semi-trailer or trailer registration. If it is a rigid truck, there is a tick box for that and the field stops being asked for.
• If it is special transport: your ACC number (Autorización Complementaria de Circulación; the regulation calls it autorización especial de circulación), who issued it (DGT or Servei Català de Trànsit) and which type it is (genérica, específica or excepcional).
• The load: what it is (nature of the goods), what it weighs, where it is collected and where it is delivered. If it is a container: type, number, seal and PIN, all optional.

One office trick: the first time round, keep this data in a note on your phone or on a laminated sheet next to the computer. From the second DeCA on, you will fill the form in from memory.

The form, step by step, and why it asks what it asks

The tool moves screen by screen, with a Next button that checks the mandatory fields before it lets you through: if something is missing, it marks it in red and tells you what it is. You can go back whenever you want without losing anything. Here is the route, grouped the way you will actually experience it.

First, the two companies. Your company (actual carrier) and your customer (contractual shipper). The law obliges both of you to make sure this document exists, so both of you are identified by NIF, plus the address in the customer's case. If your NIF is not in Spanish format you will see a warning, but you can carry on. That is the case of the foreign haulier running cabotage.

Second, the job and who is driving it. Start date and time. The DeCA has to be generated before you set off, and if you enter a date that has already passed, the tool will ask you to confirm it. The reference is optional, but it appears in the PDF file name and in the subject line of the emails: fill it in and you will save yourself more than one search later. The driver goes in with an email address, because the driver receives the document too, and then the registrations: tractor unit always, semi-trailer if there is one, "rigid vehicle" tick box if there is not. And if the trip runs under an ACC, special transport by weight or by dimensions, tick the box and give the number, the issuing authority and the type. When you drive under an authorisation, that is mandatory data on the document.

Third, the load and the run. Collection point, consignee and delivery address, description of the goods and their weight, which is always mandatory. If the exact weight is hard to determine, give another magnitude: volume, packages, pallets. The container fields (type, number, seal, collection PIN and return PIN) are there because we come from the port, but they are optional. For general cargo you leave them blank and move on. Observations are your free space: access hours, contact person, reservations about the load.

Fourth, the review. One single screen with everything you have written and, highlighted, the three email addresses the document is about to go to. Read them twice. The DeCA carries third-party data and it is going to travel by email. Then you tick the confirmation box and press Send.

What happens when you press Send

At that moment the tool generates the PDF and sends it to three recipients:

• to you (the carrier), with the PDF and the edit link;
• to your customer, with the PDF and the public consultation link;
• to the driver, with the PDF and a summary of the job: collection, PIN, delivery, registrations.

All three emails carry the same subject line, DeCA de [carrier] para [customer] - [reference] - [date] [time], so that anyone can find them in two seconds, today or a year from now.

The PDF that comes out is not a scanned sheet of paper. It is generated from the data, it weighs very little, it carries the creation date and time in its metadata and, most important, it includes a QR code with a unique web address from which anyone downloads the document directly, with no user name, no password and no screens in between. That is exactly what the Resolución de 5 de junio de 2026 requires, and it is what makes the document hold up in a roadside check.

If you get something wrong: the edit link

Nobody generates a hundred DeCAs and gets all hundred right. The regulation allows for that, and so does the tool.

The edit link is in your email, valid for seven days from the first generation. You open it, you see every field on one screen, you correct whatever needs correcting and you state the reason for the change, which is mandatory: with no reason, it does not save. When you save, what the regulation asks for happens: a new version of the PDF is generated, the old data does not disappear but stays at the foot of the document marked as not valid, with its date, its time and its reason, and the new version flies off to the three addresses again with the subject line preceded by "Actualizado:".

Two things worth knowing:

• The web address and the QR code do not change. The copy the driver already has still works and always points to the latest version. Nothing to resend and nothing to explain.
• Changing vehicle in the middle of a job works the same way. The tractor unit fails and another one goes out: you go in through the link, change the registrations, give the reason ("tractor unit breakdown") and the document is traced, as the regulation requires.

What does not work is correcting the printed copy with a biro. Handwritten notes count for nothing. And once the seven days are up, the link expires. If you need to change something after that, you generate a new DeCA, which is five minutes.

On the road: what you show the officer

This is the part that is worth knowing in advance. The DeCA is electronic: there is nothing to print and nothing to sign. The driver only needs a phone.

1. The officer stops you and asks for the control document.
2. You show the PDF on the phone, the one from the email you received, or the QR code printed on it.
3. The officer scans the QR and the document downloads straight onto their device: no viewer, no buttons, nothing asked of them.

One habit that is worth gold: before setting off, open the attached PDF once on the phone so that it stays available offline. If there is no signal at the checkpoint and the QR does not load, the attached PDF is the same document and has the same validity. The web address, for its part, stays live for at least the seven days after the job, as the regulation requires. In this tool it stays live indefinitely.

Would you rather carry it on paper as well? You can: print the PDF with its QR code and take it as a backup. The original is still the electronic one, and the paper is a courtesy copy.

Who keeps what, and who answers for what

After the job the document does not go in the bin. You and your customer both have to keep a copy for at least one year, at the disposal of the Inspección. The email does that job: file it with the rest of the paperwork for the job and you are done. In the tool, the document link does not expire either.

One detail heads off most arguments: responsibility is split by the regulation itself. The contractual shipper answers for the accuracy of the shipper's own data, meaning who they are, who is carrying for them, origin, destination and goods. The actual carrier answers for the carrier's own data: the ACC if there is one, the date and the registrations. That is why the customer gets a copy as well. If the customer spots a mistake in their data, they can ask you to correct it inside the editing window, and the change is recorded on the document itself.