GOBL to TicketBAI

May 19, 2026 · View on GitHub

Go library to convert GOBL invoices into TicketBAI declarations and send them to the Basque Country web services.

This library assumes that clients will handle a local database of previous invoices in order to comply with the local requirements of chaining all invoices together.

Copyright Invopop Ltd. 2023. Released publicly under the GNU Affero General Public License v3.0. For commercial licenses please contact the dev team at invopop. For contributions to this library to be accepted, we will require you to accept transferring your copyright to Invopop Ltd.

Source

The basque country is split into 4 "foral" tax agencies. 3 of those tax agencies decided to adopt the TicketBAI format. Each of the three agencies has their own set of documentation and integration definitions.

Links to key information for each agency are described in the following subchapters.

Bizkaia

Usage

Go Package

You must have first created a GOBL Envelope containing an Invoice that you'd like to send to one of the TicketBAI web services.

For the document to be converted, the supplier contained in the invoice should have a "Tax ID" with the country set to ES.

TicketBAI is used by three different tax agencies (Haciendas Forales), each of which has their own API and specific requirements. The es-tbai-region extension defined in the GOBL Invoice's tax property is used to set the determine the correct API to utilize. This will be set automatically in most cases.

The following is an example of how the GOBL TicketBAI package could be used:

package main

import (
	"encoding/json"
	"fmt"
	"os"

	"github.com/invopop/gobl"
	ticketbai "github.com/invopop/gobl.ticketbai"
	"github.com/invopop/xmldsig"
)

func main() {
	ctx := context.Background()

	// Load sample envelope:
	data, _ := os.ReadFile("./test/data/sample-invoice.json")

	env := new(gobl.Envelope)
	if err := json.Unmarshal(data, env); err != nil {
		panic(err)
	}
	zone := ticketbai.ZoneFor(env)

	// Prepare software configuration:
	soft := &ticketbai.Software{
		License: "XYZ",        // provided by tax agency
		NIF:     "B123456789", // Software company's tax code
		Name:    "Invopop",    // Name of application
		Version: "v0.1.0",     // Software version
	}

	// Load sample certificate:
	cert, err := xmldsig.LoadCertificate(
		"./test/certs/EnpresaZigilua_SelloDeEmpresa.p12", "IZDesa2025")
	if err != nil {
		panic(err)
	}

	// Instantiate the TicketBAI client with sofrward config
	// and specific zone.
	tc, err := ticketbai.New(soft, zone,
		ticketbai.WithCertificate(cert), // Use the certificate previously loaded
		ticketbai.WithSupplierIssuer(),  // The issuer is the invoice's supplier
		ticketbai.InTesting(),           // Use the tax agency testing environment
	)
	if err != nil {
		panic(err)
	}

	// Create a new TBAI document:
	doc, err := tc.Convert(env)
	if err != nil {
		panic(err)
	}

	// Create the document fingerprint
	// Assume here that we don't have a previous chain data object.
	if err = tc.Fingerprint(doc, nil); err != nil {
		panic(err)
	}

	// Sign the document:
	if err := tc.Sign(doc, env); err != nil {
		panic(err)
	}

	// Create the XML output
	bytes, err := doc.BytesIndent()
	if err != nil {
		panic(err)
	}

	// Do something with the output, you probably want to store
	// it somewhere.
	fmt.Println("Document created:\n", string(bytes))

	// Grab and persist the Chain Data somewhere so you can use this
	// for the next call to the Fingerprint method.
	cd := doc.ChainData()

	// Send to TicketBAI, if rejected, you'll want to fix any
	// issues and send in a new XML document. The original
	// version should not be modified.
	if err := tc.Post(ctx, doc); err != nil {
		panic(err)
	}

}

Command Line

The GOBL TicketBAI package tool also includes a command line helper. You can find pre-built gobl.cfdi binaries in the github repository, or install manually in your Go environment with:

go install github.com/invopop/gobl.ticketbai

We recommend using a .env file to prepare configuration settings, although all parameters can be set using command line flags. Heres an example:

CERTIFICATE_PATH="./test/certs/EntitateOrdezkaria_RepresentanteDeEntidad.p12"
CERTIFICATE_PASSWORD=IZDesa2025
SOFTWARE_COMPANY_NIF=A99800005
SOFTWARE_COMPANY_NAME="SOFTWARE GARANTE TICKETBAI PRUEBA"
SOFTWARE_NAME="Invopop"
SOFTWARE_LICENSE="TBAIBI00000000PRUEBA" # BI & SS
SOFTWARE_VERSION="1.0"

The SOFTWARE_* values above are the public test identity published by Batuz alongside the sandbox licence TBAIBI00000000PRUEBA. Using any other combination with this licence will be rejected.

To convert a document to XML, run:

gobl.ticketbai convert ./test/data/sample-invoice.json

To submit to the tax agency testing environment:

gobl.ticketbai send ./test/data/sample-invoice.json

Limitations

  • Tickebai allows more than one customer per invoice, but GOBL only has one possible customer.

  • Invoices should have a note of type general that will be used as a general description of the invoice. If an invoice is missing this info, it will be rejected with an error.

  • GOBL's corrective invoices aren't supported at the moment. Only credit and debit notes are, and they are converted into "Facturas Rectificativas por Diferencias" with either positive or inverted quantities depending on whether it is a debit or a credit note.

Bizkaia: Modelo 140 vs Modelo 240

Bizkaia's LROE / Batuz system uses two different registers depending on the type of issuer:

  • Modelo 240 — for legal entities (persona jurídica, NIF/CIF starting with a letter, e.g. B64847106).
  • Modelo 140 — for individuals (persona física, DNI / NIE / non-resident IDs, e.g. 12345678Z).

The library detects which model to use automatically from the supplier's tax identity, using GOBL's es.TaxIdentityKey helper. No configuration is required.

When the supplier is an individual in Bizkaia, their IAE-style activity code (Epígrafe) must be set on the supplier's ext map under the es-tbai-bi-activity key. This value is published in the <Renta> block of the Modelo 140 LROE submission. Reference:

"supplier": {
  "name": "Ana Fernández García",
  "tax_id": { "country": "ES", "code": "12345678Z" },
  "ext": { "es-tbai-bi-activity": "722300" }
}

Álava (VI) and Gipuzkoa (SS) are unaffected — their gateways do not expose model selection.

Tags, Keys and Extensions

In order to provide the supplier specific data required by TicketBAI, invoices need to include a bit of extra data. We've managed to simplify these into specific cases.

Tax Tags

Invoice tax tags can be added to invoice documents in order to reflect a special situation. The following schemes are supported:

  • simplified-scheme - a retailer operating under a simplified tax regime (regimen simplificado) that must indicate that all of their sales are under this scheme. This implies that all operations in the invoice will have the OperacionEnRecargoDeEquivalenciaORegimenSimplificado tag set to S.
  • reverse-charge - B2B services or goods sold to a tax registered EU member who will pay VAT on the suppliers behalf. Implies that all items will be classified under the TipoNoExenta value of S2.
  • customer-rates - B2C services, specifically for the EU digital goods act (2015) which imply local taxes will be applied. All items will specify the DetalleNoSujeta cause of RL.

Tax Extensions

The following extension can be applied to each line tax:

  • es-tbai-product – allows to correctly group the invoice's lines taxes in the TicketBAI breakdowns (a.k.a. desgloses). These are the valid values:

    • services - indicates that the product being sold is a service (as opposed to a physical good). Services are accounted in the DesgloseTipoOperacion > PrestacionServicios breakdown of invoices to foreign customers. By default, all items are considered services.
    • goods - indicates that the product being sold is a physical good. Products are accounted in the DesgloseTipoOperacion > Entrega breakdown of invoices to foreign customers.
    • resale - indicates that a line item is sold without modification from a provider under the Equalisation Charge scheme. (This implies that the OperacionEnRecargoDeEquivalenciaORegimenSimplificado tag will be set to S).

  • es-tbai-exemption - identifies the specific TicketBAI reason code as to why taxes should not be applied to the line according to the whole set of exemptions or not-subject scenarios defined in the law. It has to be set along with the tax rate value of exempt. These are the valid values:

    • E1 – Exenta por el artículo 20 de la Norma Foral del IVA
    • E2 – Exenta por el artículo 21 de la Norma Foral del IVA
    • E3 – Exenta por el artículo 22 de la Norma Foral del IVA
    • E4 – Exenta por el artículo 23 y 24 de la Norma Foral del IVA
    • E5 – Exenta por el artículo 25 de la Norma Foral del IVA
    • E6 – Exenta por otra causa
    • OT – No sujeto por el artículo 7 de la Norma Foral de IVA / Otros supuestos
    • RL – No sujeto por reglas de localización (*)

(*) As noted elsewhere, RL will be set automatically set in invoices using the customer-rates tax tag. It can also be set explicitly using the es-tbai-exemption extension in invoices not using that tag.

  • es-tbai-regime - sets the ClaveRegimenIvaOpTrascendencia field per VAT/IGIC tax combo. Codes follow the TicketBAI XSD list (01–17, 51–53). If not provided, GOBL fills it in during normalization from per-combo signals — tax.KeyExport → 02, equivalence-surcharge rate → 51, the invoice-level simplified-scheme tag → 52, otherwise 01. Set it explicitly when none of those defaults applies (e.g. travel agencies → 05, cash accounting → 07, OSS/IOSS → 17); explicit values are always preserved.

  • es-tbai-identity-type - sets the IDType value under IDOtro for the customer's identity (L7 list, codes 02–06). Normalization maps org.IdentityKeyPassport → 03, IdentityKeyForeign → 04, IdentityKeyResident → 05, IdentityKeyOther → 06. Set it explicitly on an identity with no key (or to override). Spanish NIFs use the NIF field directly, and EU/non-EU tax IDs map to IDOtro/IDType 02/04 automatically.

Use-Cases

Under what situations should the TicketBAI system be expected to function:

  • B2B & B2C: regular national invoice with VAT. Operation with minimal data.
  • B2B Provider to Retailer: Include equalisation surcharge VAT rates
  • B2B Retailer: Same as regular invoice, except with invoice lines that include ext[es-tbai-product] = resale when the goods being provided are being sold without modification (recargo de equivalencia), very much related to the next point.
  • B2B Retailer Simplified: Include the simplified scheme key. (This implies that the OperacionEnRecargoDeEquivalenciaORegimenSimplificado tag will be set to S).
  • EU B2B: Reverse charge EU export, scheme: reverse-charge taxes calculated, but not applied to totals. By default all line items assumed to be services. Individual lines can use the ext[es-tbai-product] = goods value to identify when the line is a physical good. Operations like this are normally assigned the TipoNoExenta value of S2. If however the service or goods are exempt of tax, each line's tax ext[exempt] field can be used to identify a reason.
  • EU B2C Digital Goods: use tax tag customer-rates, that applies VAT according to customer location. In TicketBAI, these cases are "not subject" to tax, and thus should have the cause RL (por reglas de localización).

Test Data

Sample GOBL envelopes live in test/data/*.json and their converted XML counterparts in test/data/out/*.xml. The fixtures use the Bizkaia sandbox test entity (S7836107H, "ZIURTAPEN ZERBITZU ENPRESA-EMPRESA CERTIFICACION Y SERVICIOS IZENPE SA") so they can be sent against Batuz' developer endpoint without further editing.

Regenerating the fixtures

If you edit any of the JSON inputs (for example to change the supplier), the envelope head.dig and the converted XML need refreshing. Run:

go test . --update

That recomputes the digests in test/data/*.json and rewrites every test/data/out/*.xml from the converted output. TestXMLGeneration also validates each generated XML against the TicketBAI XSD on every run, regardless of --update. Use go test . rather than go test ./... because --update is only defined for the root and convert test binaries.

XSD validation is pure Go via lestrrat-go/helium — no cgo, no system libraries. The wrapper schema in test/schema/schema.xsd pre-imports a local copy of the W3C xmldsig-core-schema.xsd so no network access is required at test time.

Sending to the Bizkaia sandbox

send-test.sh at the repo root wraps gobl-tbai send with the Bizkaia sandbox cert and the public Batuz test licence baked in:

./send-test.sh test/data/sample-invoice.json

It rebuilds bin/gobl-tbai on each invocation and POSTs to https://pruesarrerak.bizkaia.eus. Any extra flags after the filename are forwarded to the CLI (e.g. --prev '{...}' to chain).

The script expects:

  • Cert: test/certs/EntitateOrdezkaria_RepresentanteDeEntidad.p12, password IZDesa2025. This is an Izenpe sandbox cert representing the fictitious entity S7836107H. Izenpe rotates these every ~4 years; when they expire (currently 2029) grab a fresh pack from the Izenpe "Garatzaileak / Desarrolladores" download page and update both the .p12 and the *_pin.txt files in test/certs/.
  • Software identity: the public Batuz test values (A99800005 / SOFTWARE GARANTE TICKETBAI PRUEBA) paired with licence TBAIBI00000000PRUEBA. Batuz validates this combination on submission.
  • Supplier: the invoice's supplier must use the cert's entity — that's why all bundled fixtures use S7836107H and the matching legal name. A mismatch triggers N3_0000001 (cert not trusted for the supplier) or N3_0000002 (legal-name mismatch).

Common rejection codes when iterating:

CodeMeaningWhere to look
N3_0000001Signature not trusted for the supplier NIFCert expired, or the cert's organizationIdentifier doesn't match the invoice's supplier.tax_id.code
N3_0000002Supplier legal name doesn't match the NIFUpdate supplier.name to whatever Batuz returns in the error
B4_2000013NIF-IVA tiene un formato erróneoEU customer VATs are validated live against VIES; the bundled invoice-es-nl-tbai-exempt.json uses a placeholder NL VAT (000099995B57) that fails VIES and is not submittable — substitute a known-valid VAT from your own test data if you need to round-trip this fixture through the sandbox.
B4_2000026Las Claves indicadas no son compatiblesThe Bizkaia gateway rejects regime codes 19, 51, 52 and 53 — even though the TicketBAI XSD allows them and the Gipuzkoa/Araba gateways accept them. This is why sample-invoice.json (which legitimately produces 51 via its general+eqs rate, and is our regression case for the surcharge bug) won't round-trip through Bizkaia; use one of the general-rate fixtures (e.g. sample-invoice2.json) for submission tests.
pkcs12: decryption password incorrectWrong cert passwordCheck test/certs/*_pin.txt for the current pin (it's IZDesa2025 for the 2025–2029 pack)

The Araba and Gipuzkoa sandboxes need their own cert + licence packs; send-test.sh only covers Bizkaia. (In practice the Gipuzkoa sandbox currently accepts the Bizkaia developer software identity, but don't rely on it.)