Form 29 (F29) Simulator
Estimate what you have to pay this month on Form 29: net VAT, provisional monthly payments (PPM) and withholding on professional-fee receipts. Below is how each component is calculated, the deadlines that get overlooked, and what this simulator deliberately does not cover.
Written by Claudio Cortés, Public Accountant & Auditor and Master in Taxation (U. de Chile), founding partner of C&C Contadores Auditores. Published 11 August 2026. Updated 25 August 2026.
Simulate your Form 29 (F29)
Estimate your monthly Form 29 (F29) total: net VAT, monthly provisional tax (PPM) and independent-contractor withholding, from your month's figures.
Does not cover special regimes (Pro Pyme Transparente, change of VAT subject, exporter/construction VAT), the Art. 27 bis VAT refund, or payroll withholding tax. Does not replace the SII's automatic F29 proposal.
In brief
The monthly Form 29 total is the sum of three components: net VAT, provisional monthly payments and withholding on professional-fee receipts. Net VAT is output VAT —net taxable sales at 19%— less the month’s input VAT plus the credit carried over from the previous month. If the result is zero or negative no VAT is paid: it becomes a credit carried forward to the following month.
Two things that are often confused. The general deadline falls on the 12th; the extension to the 20th requires being an electronic invoicer and also filing and paying inside sii.cl — issuing electronic documents is not enough. With no activity in the period a return is still due, up to the 28th. And the provisional payment rate cannot be assumed: it is specific to each company and is recalculated every April from the outcome of the annual tax return.
- What this simulator estimates
- How net VAT is calculated
- Provisional monthly payments: why we ask for your rate
- Withholding on professional-fee receipts
- When Form 29 is due
- What it does not calculate, and why
- Frequently asked questions
- Sources and regulations
What this simulator estimates
Form 29 brings together several different obligations in a single return. This simulator estimates the three that account for most of a small or medium-sized company's monthly payment:
| Component | How it is calculated | Legal basis |
|---|---|---|
| Net VAT | Output VAT − total input VAT | Value Added Tax Act |
| PPM | Gross monthly income × your company's PPM rate | Income Tax Act, article 84 letter a) |
| Withholding on professional fees | Gross fees on receipts × 15,25% in 2026 | Law No. 21,133 |
Estimated total = VAT payable (only if the net figure is positive) + PPM + withholding on professional fees.
How net VAT is calculated
| Item | Calculation |
|---|---|
| Output VAT | Net taxable sales × 19% |
| Total input VAT | (Net purchases and expenses carrying input VAT × 19%) + credit carried over from the previous month |
| Net VAT | Output VAT − total input VAT |
| If the result is positive | It is Net VAT payable |
| If the result is zero or negative | It is a credit carried forward, which rolls over to the following month. No VAT is paid that month |
Input VAT is also where most money is lost, through formal errors rather than substantive ones: acknowledgements of receipt never given, invoices disputed after the deadline, documents recorded late. They are set out in the electronic invoicing errors that cost you input VAT.
Provisional monthly payments: why we ask for your rate
There is a design decision here worth explaining, because other simulators solve it by inventing a number.
There is no generic formula for the PPM rate of an established company. The rate is specific to each company and is recalculated every April from the outcome of its annual tax return. That is why this simulator asks for it instead of assuming it.
| Situation | PPM rate |
|---|---|
| First VAT return or first financial year | 1% — the simulator sets it automatically when you tick the box |
| Established company | Its own rate, recalculated every April. Look yours up in your Electronic Tax Folder at sii.cl |
Withholding on professional-fee receipts
If your company pays people who issue professional-fee receipts, it must withhold that amount and remit it on Form 29. The rate rises every year until 2028 under Law No. 21,133 — using last year's rate is a common mistake:
| Year | Withholding rate |
|---|---|
| 2025 | 14,5% |
| 2026 | 15,25% |
| 2027 | 16% |
| 2028 | 17% |
When Form 29 is due
| Situation | Deadline |
|---|---|
| General rule | The 12th of each month |
| Extension to the 20th | Only if the company is an electronic invoicer and also files and pays inside sii.cl. Issuing electronic documents is not enough |
| No activity in the period | A return is still due, up to the 28th |
Form 29 is only one of the month's obligations. The full map —Form 50, social security contributions, PPM, the Purchases and Sales Register and information returns— is in the monthly calendar of obligations.
What it does not calculate, and why
| Not covered | Comment |
|---|---|
| Special regimes: Pro Pyme Transparente, reverse charge, and export and construction VAT | Each has its own rules, which cannot be generalised |
| VAT refund under article 27 bis | It is a different mechanism, for VAT on fixed assets. We explain it in how to recover VAT on fixed assets |
| Withholding of Second Category Single Tax on salaries | It is declared on Form 29 but depends on the full payroll |
| Additional voluntary PPM and debt remissions | They are one-off decisions, not a monthly calculation |
| It does not replace the SII's automatic Form 29 proposal | It is a reference estimate for anticipating cash, not the return itself |
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Frequently asked questions
When is Form 29 due?
The 12th of each month as a general rule. The extension to the 20th applies only if the company is an electronic invoicer and also files and pays inside sii.cl. With no activity in the period a return is still due, up to the 28th.
What is my PPM rate?
If it is your first VAT return or your first financial year, it is 1%. Once established, the rate is specific to your company and is recalculated every April from your annual tax return: you will find it in your Electronic Tax Folder at sii.cl. There is no generic formula.
What if I end up with a credit carried forward?
You pay no VAT that month and the credit rolls over to the following month as input VAT. The simulator shows it as a «credit carried forward» instead of a payment.
How much is withheld on a professional-fee receipt in 2026?
15.25%. Law No. 21,133 set a rising schedule: 14.5% in 2025, 15.25% in 2026, 16% in 2027 and 17% in 2028.
Does this replace the SII's Form 29 proposal?
No. It is a reference estimate for anticipating how much cash you need before the deadline arrives. The return is filed on the SII's proposal and your actual records.
Does it work if I am on Pro Pyme Transparente?
Not for that regime. The simulator covers the general case; Pro Pyme Transparente, reverse charge and export or construction VAT have their own rules.
If the figure surprised you, the problem is rarely the calculation. It is usually input VAT lost through formal errors, or a PPM rate that was set wrong in April. We review it against your records. Write to us on WhatsApp (wa.link/s9s7v2) or through our contact form. See also our tax compliance service.
Sources and regulations
Legislation
- Decree Law No. 825, the Value Added Tax Act: 19% VAT rate, output and input tax
- Income Tax Act, article 84 letter a): provisional monthly payments
- Law No. 21,133: schedule of increases in withholding on professional-fee receipts, 2025 to 2028
- Decree Law No. 825, article 27 bis: VAT refund on fixed assets (outside the scope of this simulator)
Chilean Internal Revenue Service (SII)
- Frequently asked questions on the PPM rate for the first financial year
- Electronic professional-fee receipts portal: withholding rates in force by year
- Automatic Form 29 proposal and Electronic Tax Folder
Reference estimate. The final return is filed on the SII's proposal and the company's actual records.
This simulator provides an estimate of a general informative nature and does not constitute tax, accounting, employment or legal advice for particular cases. It does not replace the Form 29 proposal of the Chilean Internal Revenue Service. Before making decisions about your specific situation, let us talk.