What the rule says, word for word
All electronic documents and associated documents issued by the electronic issuer-recipient must have the corresponding acceptance message as support for the validation; otherwise they cannot be used to support input tax credits or deductible expenses, nor affect self-assessed tax returns.
Electronic Documents Regulation, article 21Worth reading twice, because the consequence is harsher than people assume: having paid the invoice is not enough. Having the XML saved is not enough either. If you did not accept it, you cannot use it.
The three answers, and when each applies
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Accept
The purchase is yours, the amount is right and the tax is correct. This is the normal answer and the one that gives full input credit.
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Reject
The document is not yours: it is not your purchase, the tax number is wrong, it is a duplicate, or the contents have nothing to do with what you received. Rejecting is not “I disagree with the price”: it is “this is not mine”.
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Accept partially
Partial acceptance is not “I accept most of it”. It is the answer for when part of the document is yours and part is not, and it carries an amount you declare. It is not a middle button for when you are unsure: it is a declaration with content of its own.
The deadline: what is known and what circulates
Here it is worth being honest: the regulation does not fix a number of days. It refers to “the term established by the Tax Administration”.
A term of one month and eight business days circulates widely. It is the figure almost everyone repeats. But it is worth knowing that it appears neither in the regulation nor in the annex, which are the rules cited to justify it.
The practical recommendation, then, is twofold:
- Answer promptly, within the month in which you are going to claim that credit. That way the question of the exact deadline never arises.
- Do not build a process around a figure nobody can point to in a rule. If someone tells you the deadline with total certainty, ask them where it is written.
Who has to answer
Anyone registered as an electronic issuer-recipient — which is to say, anyone registered as a taxpayer who receives documents. It is not optional and it is not reserved for large companies. If you buy from a Costa Rican supplier who invoices you electronically, you owe an answer.
What it costs not to answer
- The input VAT is lost. That 13 % stops being deductible from what you owe each month.
- The expense stops being deductible in your income tax return.
- And it is silent. Nothing warns you. The invoice sits there, paid and saved, and the loss only appears when someone reviews the year.
The purchases that are waiting for an answer, in one list
Ticuenta receives what your suppliers issue you, shows what is still unanswered, and sends the acceptance — so the credit does not get lost for lack of a click.
See how it worksAbout this article. The quotation is article 21 of the Electronic Documents Regulation, verbatim. The widely repeated deadline of one month and eight business days is reported here as what circulates, not as what the rule says — because it does not appear in the regulation or the annex.
Verified as of 24 September 2026. Tax rules change. This is information, not tax advice.
Sources: Current legal texts (Sinalevi) Ministry of Finance