Try the unhappy paths

A DTE aceptado on the first try is the happy path. In production you’ll see rejections, documents with repairs, exhausted folios and slow SII responses — and your integration needs to handle them before they happen against a real customer. The sandbox gives you reserved receptor RUTs that trigger each outcome deterministically.

Magic RUTs don’t lie to Simplo’s state machine: they lie to the SII simulator. The real cycle — firmado → enviando → procesando → aceptado/rechazado/con_reparos, with the same events and the same transition code — runs exactly like it does in production. The only thing fabricated is the answer the (simulated) SII gives.

Magic RUTs: force the outcome from emission

Emit a DTE with one of these as receptor.rut and the outcome is decided the moment you send it — no extra endpoint call required:

Receptor RUT	Outcome	SII code
44000001-0	rechazado	EMP
44000002-9	con_reparos	DNK
44000003-7	stays in procesando (the simulator never resolves it)	DOK (non-terminal)
44000004-5	the send to the simulated SII fails as if no folios were left (CAF_NO_DISPONIBLE)	— (the send fails)
anything else	happy path: enviando → procesando → aceptado	DOK

curl -X POST https://api.simplo.cl/api/v1/billing/dte \
  -H "X-Api-Key: $SIMPLO_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
    "tipo_dte": 33,
    "receptor": { "rut": "44000001-0", "razon_social": "Cliente que rechaza" },
    "detalle": [{ "nombre": "Prueba de rechazo", "cantidad": 1, "precio": 10000 }]
  }'

44000004-5 is the odd one out: the other three emit normally (201, estado: "firmado") and the verdict diverges later, during the async cycle — just like production. 44000004-5 instead makes the send to the simulated SII fail with an exhausted-folios error (CAF_NO_DISPONIBLE — see the error table below): the emission returns 201, but the document never advances to procesando. It’s the way to rehearse the “I ran out of folios” scenario without burning through your synthetic test folios.

Magic RUTs accept the dotted/spaced format too (44.000.001-0 and 44000001-0 both match).

Magic RUTs are the sandbox’s only lever: there are no endpoints to force states on a DTE you already emitted or to reset the sandbox. If you need a specific outcome, decide it at emission, with the receptor’s RUT.

Structured error catalog

Every API failure — sandbox or production — responds with the same shape: code (machine-readable), message, action (recommended next step) and severity. Here’s what you’ll run into testing unhappy paths:

Code	Message	Recommended action	Severity
CAF_NO_DISPONIBLE	No CAF available for the document type	upload_caf	error
CAF_STOCK_LOW	Folios running low	upload_caf	warning
DTE_NOT_FOUND	DTE not found	verify_empresa_and_id	error
DTE_ESTADO_INVALIDO	DTE in a state that doesn’t allow this operation	check_dte_status	error
RUT_INVALIDO	RUT fails the mod-11 check	fix_rut_input	error
FOLIO_DUPLICADO	Folio already used	check_existing_dte	error
MONTO_INCONSISTENTE	Net + VAT doesn’t match the total	recalculate_totals	error
IDEMPOTENCY_IN_PROGRESS	This Idempotency-Key’s request is already being processed	retry_later	warning
IDEMPOTENCY_BODY_MISMATCH	The Idempotency-Key was reused with a different body	generate_new_key	warning
SII_RECHAZADO	The SII rejected the document	review_xml_errors	error
SII_DUPLICADO	The document was already sent to the SII	check_existing_envio	warning

The full catalog (certificate, export, liquidaciones and more) lives in Errors. action is designed so a coding agent can decide its next step without having to parse message as natural language.

What the sandbox does NOT simulate

A sandbox that overpromises produces the same churn it exists to prevent. Be explicit about this in your own integration too:

• XSD and real SII business-rule validation. The simulator accepts whatever XML the engine generated; the real SII rejects for reasons that only surface against its certification or production environment.
• SII certification. Passing the sandbox doesn’t get you a single day closer to being SII-certified — see Go to production.
• Real folio expiry (6 months) or certificate expiry: sandbox ones are synthetic and long-lived.
• Real SII outages, latency and rate limits, or its final codes 904/905/906.
• Intercambio (email, acknowledgements, SETMAIL).
• The PDF and XML have no tax validity — the sandbox’s CAF and certificate are synthetic and self-signed, and the real SII would reject them. The amounts and VAT ARE real, though: it’s the same calculation engine as production — only the recipient is fake.

Related

• Quickstart — the full flow, from sandbox to your first DTE
• States — the full DTE lifecycle
• Errors — the full catalog and retry rules
• Go to production — the go-live checklist