Three weeks ago we published a final checklist for the taxpayers in Groups 9 to 12. This post is for the businesses that read it, meant to act, and are now looking at the calendar.
Starting October 1, 2026, affected taxpayers must issue their fiscal documents only through their assigned modality: electronic online invoicing, computerised online invoicing, or the SIN's online Portal Web. There is no further extension on the table. Here is what that means in practice.
What actually changes on October 1
Your old invoices stop being valid documents
An invoice issued outside your assigned modality after the deadline is not a valid fiscal document. That is your problem, and it quickly becomes your client's: they cannot use it for crédito fiscal. Expect business clients to refuse or return them.
Not issuing a valid invoice becomes a closure risk
Under the Código Tributario, failing to issue an invoice is sanctioned with the closure of the establishment: 6 days for a first offence, doubling with each repeat, up to 48 days. Fines for failing formal duties can apply on top.
Your clients start asking questions
Larger clients reconcile their purchases against what the SIN has on record. An invoice that isn't there gets flagged, and the call comes to you. For B2B sellers, this is often the first place non-compliance shows up.
Don't stop invoicing. The worst response to not being ready is to pause invoicing "until the system is set up". A sale with no invoice is the one that triggers closure. If you have to, move temporarily to the SIN's free Portal Web (see step 3) and keep issuing.
The five-step recovery plan
1
Confirm your group and assigned modalityLog in to SIAT and check which modality your NIT has been assigned. Many businesses spend days preparing for the wrong one. It takes five minutes and decides everything that follows.
2
Pick your route by volume, not by priceA handful of invoices a day can be covered by the Portal Web. Anything with a point of sale, many branches or hundreds of invoices a month needs a certified system — your own, or a provider's.
3
Use the Portal Web as a bridge if you need toThe SIN's online portal lets you issue valid invoices from a browser at no cost. It is slow for high volume, but it keeps you legal while your permanent system is configured.
4
Get the technical prerequisites in orderFor the electronic modality you need a digital signature certificate from an authorised provider. Every online modality requires your CUIS and daily CUFD codes and synchronised SIN catalogues. A certified platform handles most of this for you.
5
Issue a test invoice, verify it, then tell your clientsIssue one real invoice, then check it on the SIN's verification service using the QR code. Then send your business clients a short note confirming you are issuing through the new modality. It heads off rejected invoices and payment delays.
Mistakes we see in the final week
- Buying software that isn't certified for your modality. Ask the provider for proof of SIN certification for the exact modality your NIT is assigned.
- Forgetting branches and points of sale. Each branch and point of sale must be registered in SIAT. One missing branch means that location can't invoice.
- No plan for outages. Online invoicing depends on connectivity. Learn how contingency mode works before your first internet cut, not during it.
- Leaving the RCV for later. October's sales and purchases register still closes on schedule. The switch doesn't pause your filing calendar.
If you are already late: getting into compliance quickly and documenting the steps you took is always better than waiting to see whether anyone notices. Every day of non-compliant invoicing adds to your exposure. Every compliant invoice is one less problem.
How Contably helps: Contably is a native SFE platform. It handles CUIS and CUFD codes, catalogue sync, digital signatures and contingency mode for you, and your invoices feed straight into IVA, the RCV and your books. Most businesses issue their first valid invoice the same day they sign up.
This article is general information for Bolivian businesses, not tax or legal advice. Rules and rates change; confirm how they apply to your business with your accountant or the SIN before acting.
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