One MRN per transit01
The declaration is identified by the LRN set by the holder (up to 22 characters, unique per holder) and, once accepted, by the 18-character MRN assigned by the AEAT. Since 2024, character 17 is a letter from J to M.
Customs transit
(NCTS)
Customs transit (tránsito aduanero) is the procedure that lets goods move under customs control, without paying duties or VAT, from an office of departure to an office of destination. It is declared in NCTS, the European transit system: T1 for non-Union goods and T2 for Union goods. The holder of the procedure lodges it, with a guarantee.
In Spain, the declaration is lodged at a Spanish office of departure through the transit web services of the Spanish Tax Agency (AEAT). The version of the system in force is NCTS phase 6.
What is the difference
between T1, T2 and T2F?
The difference is the customs status of the goods: T1 is for non-Union goods and T2 for Union goods. The type also decides whether offices of transit are needed and which export can continue as a transit.
| Type | Which goods | Offices of transit | If an export continues |
|---|---|---|---|
| T1 | Non-Union goods (external transit, art. 226 UCC). | Office of transit if the destination or the route touches a common transit country or Andorra. | Export EX with procedure 31, or 10 with document C651. |
| T2 | Union goods when the journey touches a common transit country: they keep the proof of their customs status (art. 227 UCC). | Office of transit always. | Export EX with procedure 10, 11, 21, 22 or 23. |
| T2F | Union goods to or from a territory outside the VAT area, such as the Canary Islands. | As for T1. | Export of type CO. |
| TIR | Road transport with a TIR carnet, with departure and destination in the EU. | No offices of transit or exit. | — |
| T1GI / T2GI | Transit to Gibraltar, in force since 15-07-2026. | None: departure from Algeciras, La Línea or Sagunto. | T1GI cites the import (H1); T2GI, the export. |
With destination San Marino, T2 or T2F is used. Source: AEAT NCTS6 Transit Web Services Guide v1.20, pp. 70-76, and Regulation (EU) 952/2013, the Union Customs Code (UCC; CAU in Spanish), arts. 226 and 227.
Who lodges it Who lodges
Who lodges
the declaration?
The holder of the transit procedure or its representative lodges it at the office of departure. Depending on the operation, the consignor, the consignee and the carrier also take part.
- 01 Holder of the procedure The principal (obligado principal): responsible for the operation and the guarantee. With a Spanish guarantee, it is identified by an EORI linked to its Spanish tax ID (NIF); in a TIR, by its TIR holder number.
- 02 Representative Direct representation only. The representative must be in the AEAT register of customs representatives and be named as representative on the guarantee.
- 03 Authorised consignor Declares from its own premises with authorisations C521 and C523 (seals), without taking the goods to the customs office.
- 04 Authorised consignee Receives the goods at its private premises with authorisation C522 and then reports the unloading result.
- 05 Carrier Declared in the operation only when it is not the holder of the procedure.
What do you need to declare
a transit in NCTS?
The holder of the procedure needs an EORI number, a guarantee with its GRN (in a TIR, the carnet) and a program that sends the declaration to the AEAT's transit web services. Otherwise, a customs representative files it, always under direct representation.
| How | What it involves | Who it suits |
|---|---|---|
| Transit software connected to the AEAT | Builds the transit declaration (CC015C) and sends it to the NCTS6 transit web services with an electronic certificate, quoting the guarantee's GRN. | Freight forwarders, hauliers and holders of the procedure who declare transits often. |
| A customs representative | Files for the holder of the procedure, only under direct representation, and must be on the AEAT's register of customs representatives. | Occasional transits. |
General information; not customs advice.
From departure to destination
How is a transit processed?
Declaration at the office of departure
The holder or its representative sends the declaration (CC015C) with its LRN. On acceptance, the AEAT assigns the MRN.
Guarantee and control channel
The guarantee is committed. On green there is release; on orange or red, documents are attached for clearance.
Release and TAD
The AEAT generates the transit accompanying document (TAD, DAT in Spanish) with its CSV and sets the time limit for arrival.
Journey and offices of transit
No binding itinerary: the lorry passes through the declared offices of transit.
Arrival and discharge
The arrival is notified (CC007C). With no discrepancies, or only minor ones, the transit is ended and the guarantee is released.
Scroll
What guarantee
is needed?
You need a guarantee that covers the import duties and other charges on the goods, identified by its guarantee reference number (GRN). The operator calculates the amount and splits it across the guarantees it cites, up to 9.
| Type | Guarantee | How it is declared |
|---|---|---|
| 0 | Guarantee waiver | With a GRN and the customs office's waiver authorisation. |
| 1 | Comprehensive | With a GRN; up to 9 per declaration. If it is Spanish, it cannot be invalid for the country of destination or the countries of transit. |
| 2 and 3 | Individual | With a GRN, single use and for an amount no higher than the reference amount. Type 3 requires a Spanish GRN. |
| 4 | Individual voucher | 24-character GRN (17 for the GRN and 7 for the voucher number), single use, with an access code and an amount to cover of up to €10,000. |
| 5 | Zero amount | No GRN. Only when the amount to be guaranteed is zero euros. |
| B | TIR carnet | No GRN and only one. It is the only one valid in a TIR, and only in a TIR. |
The holder of a Spanish guarantee must be the holder of the procedure. Source: NCTS6 guide v1.20, pp. 80-82.
At destination What happens when
What happens when
the goods arrive?
At destination, the arrival is notified with the MRN on the TAD. What follows depends on where the goods are received and who issued the transit.
Private premises The authorised consignee (C522) notifies the arrival. On green, it unloads the goods itself and reports the result once (CC044C): compliant, or with discrepancies in weights, items or seals.
Customs office or public location No authorisation or representative needed. On green, automatic discharge can be requested in the same arrival message; otherwise the customs office ends the transit.
Transit from another country If the MRN is foreign and the AEAT does not have it yet, it requests it from the country of departure and the arrival is notified again after 15 minutes. After more than 6 hours with no data, or if the data are refused, it is registered with the data on the TAD.
Passage through a port If the lorry enters by ferry through a Spanish port with the vessel's summary declaration or G4, the passage is notified (CC117D) item by item: mandatory since 23-09-2025.
What do you need
to know about NCTS6?
The TAD, with its CSV02
The AEAT generates it at release. In the final phase it is optional for it to travel with the goods; it is downloaded from the AEAT e-office (Sede) with the CSV.
Security data03
A transit can carry the security data and act as the exit summary declaration (EXS) when the goods leave the EU security area, for example a T1 from Valencia to the United Kingdom by ferry.
Pre-lodging04
You can declare before you have the goods. It does not commit the guarantee, and there are 30 days from registration to present the goods; otherwise the AEAT invalidates it.
A wider common transit area05
Georgia has been on the common transit list since 01-02-2025, and Moldova and Montenegro since 01-11-2025. With destination in a common transit country, at least one office of transit is in that country.
What about a TIR or
a transit to Gibraltar?
A TIR uses the same declaration as common transit. It carries the TIR carnet number and the TIR holder identifier, a single type B guarantee with no GRN, and departure and destination in the EU, with no offices of transit or exit.
Goods go to Gibraltar under T1GI or T2GI, in force since 15-07-2026. They leave from Algeciras, La Línea or Sagunto, with no security data, a guarantee of type 0 to 3 and a Spanish GRN. The T1GI cites the import the goods come from and the T2GI, the export.
Common questions
about transit
Short answers to the usual questions from freight forwarders, customs agents and importers.
What is NCTS?
It is the New Computerised Transit System: the European system in which Union transit and common transit operations are declared and tracked. In Spain it is used through the AEAT's transit web services, and the version in force is phase 6 (NCTS6).
What is the difference between T1 and T2?
T1 covers non-Union goods, which travel to their destination without paying duties or VAT. T2 covers Union goods when the journey touches a common transit country, and keeps the proof of their status. A T2 always has an office of transit.
Who lodges the transit declaration?
The holder of the procedure, also called the principal, or its representative. Spain only accepts direct representation, and the representative must be in the AEAT register of customs representatives.
What guarantee does a transit need?
One that covers the import duties and other charges on the goods: comprehensive, individual or a waiver, identified by its GRN. Up to 9 GRNs can be cited per declaration. In a TIR, the guarantee is the TIR carnet itself.
How long is there to reach the destination?
The AEAT calculates the time limit for arrival when it accepts the declaration and returns it in the response; the operator does not declare it. For a pre-lodged declaration, there are 30 days from registration to present the goods.
What is the TAD and does it have to be printed?
It is the transit accompanying document (DAT in Spanish). The AEAT generates it at release with a CSV, and the operator does not print it from its own system. In the final phase it is optional for it to travel with the goods.
When is a transit guarantee released?
When the transit is ended at destination with no discrepancies or with minor ones. Also if release is refused or the declaration is invalidated.
Can the balance of a comprehensive transit guarantee be checked?
Not by web service: the AEAT does not publish a transit guarantee query for operators. The reference balance of a comprehensive guarantee is checked on the AEAT e-office (Sede electrónica).
What software do you need to declare a transit in NCTS?
A program that builds the transit declaration (CC015C) and sends it to the AEAT's NCTS6 transit web services with an electronic certificate. The holder of the procedure or their representative files it, always under direct representation, quoting the guarantee's GRN.
