Dominican ITBIS IT-1 Return
Compute ITBIS by rate, validate NCF and RNC, and build the DGII Formulario IT-1 figures
This module turns your posted sales and purchase invoices into a ready-to-file Formulario IT-1 worksheet for the Dirección General de Impuestos Internos (DGII) of the Dominican Republic. It classifies every line by its statutory ITBIS rate, computes the tax owed and the tax you may deduct, applies the withholdings suffered and your prior credit balance, and prints the exact casilla figures you transcribe into the DGII Oficina Virtual.
Built around the real DGII rules
ITBIS by statutory rate
Lines are grouped into the three statutory ITBIS rates: 18% (tasa general), 16% (tasa reducida) and 0% / exento. Output tax (ITBIS facturado) and deductible input tax (ITBIS adelantado) are computed per rate with a deterministic, two-decimal HALF-UP money policy.
NCF / e-NCF validation
Every Número de Comprobante Fiscal is parsed and validated: pre-printed 11-char B series, 13-char electronic e-CF (E series), and legacy 19-char formats. The document-type code drives whether a purchase grants a deductible ITBIS credit (crédito fiscal) - consumo (02/32) invoices correctly do not.
RNC & cédula check digits
Company, partner and withholding-agent identifiers are checked with the official DGII control-digit algorithm: 9-digit RNC (weights 7-9-8-6-5-4-3-2, mod 11) and 11-digit cédula (Luhn mod 10). Bad identifiers are blocked before you file.
Withholding tracking
Capture the ITBIS withheld from you by third parties - large taxpayers, the State (Norma 07-2009) and card processors - per regime, with base, rate and source invoice. The total flows into casilla 40 and reduces the ITBIS payable.
IT-1 casilla worksheet
| Casilla | Concept |
|---|---|
| 1 | Total operations of the period |
| 3 | Taxed operations (18% + 16%) |
| 6 | Exempt / zero-rated operations |
| 11 / 12 | Taxable base at 18% / 16% |
| 16 / 17 | ITBIS billed at 18% / 16% |
| 20 | Total ITBIS billed on sales |
| 25 | Deductible / advanced ITBIS on purchases |
| 29 | Prior period credit balance |
| 40 | ITBIS withheld by third parties |
| 38 | Total ITBIS payable |
| 39 | Credit balance carried forward |
Pre-filing validation
Before you transcribe anything into the Oficina Virtual, the module runs the IT-1 control set inside Odoo: company RNC control digit, valid filing month, per-rate base/tax consistency, output tax equal to the sum of per-rate ITBIS, mutually exclusive payable vs credit, and structural NCF/RNC checks on every line. Blocking errors are listed so you fix the data in Odoo rather than round-tripping the DGII tool.
Deterministic output
The worksheet is produced as readable text plus a flat CSV of every casilla, so the figures are auditable and reproducible to the cent.
One-click monthly wizard
Pick a year and month, confirm the company RNC, set any prior credit, and the wizard creates and computes the IT-1 return in a single step.
Scope & boundary
This is a pure figures generator. It computes and presents the IT-1 declaration figures and worksheet from data already in your Odoo database. It does not transmit anything to the DGII and is not a certified filing agent - you file the IT-1 yourself through the DGII Oficina Virtual with your own credentials.
Built on the Odoo Community account base, it installs on Odoo 18 and 19
with no Enterprise dependency.
Screenshots
Generate It 1
It 1 Returns
Withholdings
Update date: 2026-07-02