How to check a return before submitting it

What is it for?

Before you validate a VAT return, fiscaldoo checks it against a list of automatic checks: whether the VAT equals the base times the rate, whether there are unposted documents in the period, whether the certified accountant is given, whether the amounts changed after the calculation, among others. Each check comes out OK, Warning or Blocking. A Blocking result prevents validation; a Warning only asks you to review.

This article explains each result and what to do. The full path of the return (calculate, annexes, validate, export) is in How to prepare the periodic VAT return.

When to use it?

• After Calculate and before Validate.
• When the screen refuses Validate or Record submission and says there are “blocking check(s)”.
• After posting or correcting documents of the period, to confirm that the return is still right.
• Do not use them as a guarantee that the return is correct in the eyes of the AT: the checks confirm the internal consistency of the amounts and data, not the tax treatment of the operations.

Where to find it?

Accounting › Declare › VAT › What is there to do with the VAT? › Prepare the VAT return, and in the open return, the Checks tab. The list of returns already created is on the same page, in Supporting lists › VAT return records.

Before you start

• Your profile is Accountant. With it you run the checks and see the results (tested with the Accountant profile). Validate and Send back to draft belong to other profiles (see periodic VAT return).
• The return for the period has been created. The example is the September 2026 return (2026/9, v1) of Empresa Demonstração, Lda, which in the demo is already Validated: the checks also run on a validated return.

How to use it

1. Open Accounting › Declare › VAT › What is there to do with the VAT? and click Prepare the VAT return. The return for the period opens.
2. Open the Checks tab and click Run checks. At the top, the counters Blocking checks and Warnings appear. Below, one line per check, with Result, Check, Message and Documents to fix. The Blocking and Warning lines come first. With everything in order, the demo shows 19 checks and only 1 Warning: Period closed to VAT.
3. To see what happens with a draft in the period, create a draft supplier bill dated September 2026 and run the checks again. In the example, a bill from Papelaria Central, Lda with the Bill Reference FT PC/2026/1187 and the Bill Date 25/09/2026, saved without confirming. The Accounting Date was set to today and was changed by hand to 25/09/2026: it is this date that puts the draft in the period. Blocking appears in Entries still unposted in the period: “The period has 1 unposted entry(ies), e.g. Draft supplier bill (FT PC/2026/1187). What happened: when they are posted they change the declaration, so the submission is blocked while they exist. How to fix it: post or cancel them, then compute again.” The document appears in Documents to fix.
4. Fix the cause and run again. In the example, cancelling the draft removes the Blocking result. If you post the document instead of cancelling it, the return no longer matches the calculation (next step).
5. If you post a document of the period after the return has been calculated, Accounting data unchanged since the calculation becomes a Warning with the message “The accounting data changed since the declaration was calculated (fields 24, 91, 93). How to fix it: use “Send back to draft” (Fiscal Administration) and then “Calculate”.” The fields shown are the ones that changed. On Record submission, the same check becomes blocking (the case is in “Registar submissão é recusado porque os dados mudaram” (Record submission is refused because the data changed), in the periodic VAT return).
6. The returns for October, November and December 2026 (drafts, after Calculate) show other checks with alerts. In November's, with a supplier bill of €100,000.00 for equipment posted in November for the example, besides the Blocking result for unposted entries these appear: Notes from the calculation (“The calculation reported 2 note(s): a previous period with entries but no return submitted…”), Certified accountant (Box 20), Period closed to VAT, Credit to recover without refund request (“The declaration has €22,972.40 of VAT to recover and no refund was requested. What happened: the amount is carried to the next period (field 96). How to fix it: if you want it refunded, fill in field 95 (“Edit field 95”) and compute again; otherwise nothing to do.”) and The previous period is settled (“The previous period (October 2026) still has VAT to settle: it was not settled and its return is not validated or delivered. … How to fix it: settle October 2026 first (menu “VAT period settlement”). Until then the figures of this period may change.”).
7. Quadro 20 changes its message depending on the company. Without saying whether it has organised accounting (the starting value): “The Certified Accountant of Quadro 20 is not filled in and the company did not say if it has organized accounting. How to fix it: set “Organized accounting” in the company (tab Localização PT)…”. With organised accounting Yes and no accountant: “… the company has organized accounting, so the return must identify the Certified Accountant, otherwise the AT refuses it. How to fix it: in the “Quadros 05 and 20” section choose a Certified Accountant registered in the company (with a valid NIF).” With a contact with a valid NIF who is not registered as the company's accountant: “Contabilista de exemplo sem NIF is not a Certified Accountant registered in the company. How to fix it: register the accountant in Accounting › Configure › Security and data › Certified accountant, or choose a registered one in Quadro 20.” With No: OK, “The company has no organized accounting: Quadro 20 (Certified Accountant) does not have to be filled in.” A contact without a valid NIF cannot even be chosen: “The Certified Accountant “…” has no valid NIF. What happened: Quadro 20 identifies the accountant by NIF. How to fix it: correct the NIF in the contact.”
8. If Quadro 05 is ticked (“no operations”) on a return with amounts, the check becomes Blocking: “Quadro 05 says there were no operations but fields 1, 2, 3, 4 have values. What happened: the declaration with no operations must have fields 1 to 24, 40 and 41 at zero. How to fix it: untick Quadro 05 or correct the accounting.” Ticking Quadro 05 against the calculated value requires the Reason for changing Quadro 05: without it the screen refuses (“Quadro 05 differs from the calculated value (all fields 1 to 24 at zero). What happened: it can only be changed with a reason. How to fix it: fill in “Reason for changing Quadro 05”.”).
9. VAT equals base times rate. If a document of the period has a tax different from the base times the rate (for example, the tax amount edited by hand on a €1,000.00 invoice at 23 %, with €300.00 of VAT instead of €230.00), the check becomes Blocking and names the document: “Document FT D26/46, tax 23%: the VAT is €300.00, but the base €1,000.00 times the rate gives €230.00 (difference €70.00; tolerance €0.01). What happened: the document's VAT is not equal to the base times the rate. How to fix it: correct the document's tax lines (or the tax used on its lines) so that the VAT equals the base times the rate, and calculate the return again.” The invoice appears in Documents to fix. An invoice already issued cannot be changed: see I cannot change a certified document and talk to the certified accountant before correcting.
10. Adjustment annexes. The VAT on credit notes with VAT goes to field 40 (in favour of the taxable person) or 41 (in favour of the State), and each amount must be listed in the Annexes 40 and 41 tab. With a credit note of €906.43 of VAT and an annex that only adds up to €50.00, Blocking appears: “The annex of field 40 adds up to €50.00 but field 40 is €906.43. What happened: all the amounts of fields 40 and 41 must be listed in the Regularizations annex (DP IVA instructions). How to fix it: pre-fill the annex from the regularization notes and add the manual lines.” An annex line with no Reason (art. 78.º) and no Legal basis gives the Warning “1 annex line(s) have no reason. How to fix it: choose the reason of the regularization or write the legal basis in each line.” (blocking when recording the submission). With the Pre-fill from the regularization notes button (only the Fiscal officer sees it; the Accountant does not), the annex gets the line of the note, and if the €50.00 manual line stays, the total (€956.43) is above the field and the warning becomes Adjustments annexes exceed the fields: “The annex of field 40 adds up to €956.43, more than field 40 (€906.43). … How to fix it: confirm that those lines are not already in the field and that the field takes them into account.” Only the Fiscal officer and the Fiscal administration write in the manual lines of the annex; the Accountant gets “Only the Fiscal Administration and the Fiscal Officer can edit the manual fields of a VAT return.”
11. Negative values in the fields. A €700.00 credit note on an exempt June invoice, issued in October with the adjustment reason of art. 78, paragraph 2 (the note requires the reason, the proof of the adjustment and the reference date to be posted), makes the month's exempt sales fall below zero: Warning “Fields 9, 90 have negative values. What happened: credit notes or corrections are larger than the sales in the period. How to fix it: check these fields in the drill-down; if they are right, nothing to do.” It does not block.
12. Credit notes of exempt operations. The same note gives the Warning “1 credit note(s) of exempt operations (no VAT) reduce the base of fields 8/9 in the period of the note. What happened: fields 40/41 stay at 0.00 for them (CIVA art. 78), but the base is not always corrected in the period of the note: it depends on the type of exemption and the reason for the note. How to fix it: decide for each note; if the correction belongs to the period of the original invoice, tick “Correct in the period of the original invoice” on the note and replace the VAT return of that period; otherwise, confirm with the accountant.” The credit note appears in Documents to fix.
13. Accounts of the period to review. With two accounts (121 and 2111) in Account reviews in the “To review” state and with dates within the period, the Warning says: “2 account(s) of the period are still to review or have an unusual balance, e.g. 121, 2111. What happened: the review of the accounts of the period is not finished, so the declaration may still change. How to fix it: review them in Account reviews, then run the checks again.” It never blocks.
14. Mandatory data. If you delete the answer to Quadro 04 (recapitulative statement) on a draft return, the check becomes a Warning (and Blocking when recording the submission): “VAT return “Empresa Demonstração, Lda — 2026/10 (v1)” is not ready: it needs the answer to Quadro 04 (recapitulative statement). What happened: these data are mandatory in the declaration. How to fix it: fill them in on the return.” The text lists each missing item; the NIF and the location of the head office cannot be deleted (see below).
15. Totals and official formulas. If a total field does not follow the formula (field 10 different from 12 + 14 + 15, field 11 different from 13, or 90 to 94 different from the official formulas), Blocking appears: “The totals of Quadro 06 are not coherent: field 10 is €10.00, it should be €0.00 (= 12 + 14 + 15); field 90 is €0.00, the official formula gives €10.00. What happened: the declaration was changed or calculated by an older version. How to fix it: use “Send back to draft” (Fiscal Administration) and then “Calculate”.” At the same time, Accounting data unchanged since the calculation becomes a Warning (“… (fields 10) …”). The screen does not let you type numbers in the fields (the amounts are always calculated), so this check cannot be triggered on screen: it was reproduced by simulation, changing field 10 outside the screen, and the screenshot shows that forced state.
16. Credit brought forward. Field 61 follows field 96 of the previous return while the previous one can still be recalculated: validating September updates October's field 61. If the October return is already Validated and September's is sent back to draft, changed (a September supplier bill) and validated again, October keeps the old credit and the Warning says: “The credit brought forward (field 61: €2,089.32) is not the credit carried forward by the previous declaration “Empresa Demonstração, Lda — 2026/9 (v1)” (field 96: €2,549.32). What happened: the previous declaration was changed or replaced. How to fix it: use “Send back to draft” (Fiscal Administration) and then “Calculate”.” (blocking when recording the submission).
17. When there is no Blocking result, go on to Validate. Warnings do not prevent validation, but read them one by one (table below).

Pending validation by a certified accountant: the relationships between the return fields (totals, official formulas and annexes) that each check verifies.

What each check verifies

The names and messages are those on screen. For the checks that were triggered (steps 3 to 16) the message is the real one. For the others, the “When it alerts” column says what each one verifies and below the table is the reason they were not triggered.

Check	When it alerts	What to do
Entries still unposted in the period	There are drafts dated in the period. Blocking.	Post or cancel the documents in the Documents to fix column and use Calculate.
Period closed to VAT	“The period is not closed to VAT: no VAT lock date is set.” Warning, and it is the normal state before submitting.	After submitting, set the VAT lock date at the end of the period (lock dates). Only users with the “Fiscal Submissions” group can raise the date: the Administrator has it, the Certified accountant profile does not. With this profile, in Accounting › Close › Close the month › Lock dates, the Tax Return Lock Date is refused on Apply: “Your profile cannot raise the “Tax Return Lock Date” of Empresa Demonstração, Lda: it needs the group "Fiscal Submissions". Ask a user with that profile to do it.”
Accounting data unchanged since the calculation	Some document of the period changed after the calculation.	On a validated return, Send back to draft (Fiscal administration profile) and Calculate.
VAT equals base times rate	The VAT of fields 2, 4 and 6 is not equal to the base times the rate on a document (message in step 9). Blocking.	Open the document and correct the rate or the amounts.
Totals and official formulas	Fields 10, 11 and 90 to 94 do not follow the official formulas (message in step 15). Blocking.	Send the return back to draft (Fiscal administration) and use Calculate again.
Box 05 (no operations)	Quadro 05 is ticked and there are amounts in the fields (message in step 8), or the opposite. Blocking.	Calculate again and check Quadro 05.
Adjustments annexes match fields 40 and 41, Adjustments annexes exceed the fields and Reason stated in every adjustment	The annex adds up to less than the field (Blocking), to more (Warning), or a line has no reason (Warning; Blocking on submission). Messages in step 10. With everything right, the screen only shows the first one, on one line: “The annexes of fields 40 and 41 add up to the fields and every line has a reason.” That is why the demo shows 19 checks.	Review the Annexes 40 and 41 tab (adjustments) and pre-fill it from the notes.
Certified accountant (Box 20)	Not filled in, has no valid NIF or is not an accountant registered in the company (messages in step 7). Warning on manual calculation and Blocking on validation or submission, or when the company configures it that way.	Choose it in the “Quadros 05 and 20” section and register it in the company.
Mandatory data filled in	The NIF, the location of the head office or the answer to Quadro 04 is missing (message in step 14). Warning; Blocking on submission.	Fill in the missing answer on the return.
Credit to recover without refund request	There is VAT to recover and field 95 is empty: the credit is carried forward (message in step 6). Warning.	Fill in field 95 to request the refund, or let the credit pass to the next period.
Credit brought forward equals the previous declaration	Field 61 is not equal to field 96 of the previous return (message in step 16). Warning; Blocking on submission.	Send this return back to draft (Fiscal administration) and use Calculate.
Negative values in the fields	Bases or taxes that are normally positive came out negative (message in step 11). Warning.	Open the documents of the field and see what makes them negative.
Accounts of the period still to review	The review of the period's accounts has accounts to review or with an unusual balance (message in step 13). Warning.	Finish the account review.
Credit notes of exempt operations: period of the correction	A credit note of an exempt operation counts in fields 8 or 9 of the period of the note (message in step 12). Warning.	Decide the period of the correction for each note.
Notes with value and no art. 78.º reason	There is a credit or debit note with an amount or VAT without the art. 78 reason.	Give the reason on the note.
Box 06-D total equals field 8 and Fields 103 and 104 equal their detail	They only exist in periods starting on or after 01/07/2027; before that, they come out OK with that explanation.	Nothing to do in 2026.
The previous period is settled	The previous period has VAT to settle (message in step 6). Warning.	Do the VAT settlement of the previous period.
The period was not delivered in the previous system	The period has already been declared in the program the company used before fiscaldoo, as recorded in the migration. Warning on calculation; Blocking on validation and submission. In the demo it comes out OK: “The period was not delivered in the previous system.”	Do not submit the return for that period: it has already been submitted.

Not triggered: The period was not delivered in the previous system only alerts in a company that came from another program and recorded in the migration the last VAT return submitted there; Empresa Demonstração did not come from another program. Notes with value and no art. 78.º reason cannot be triggered: the product no longer lets you post a note without a reason, and the check only warns about notes posted before that rule (hence the warning about “posted before the reason was mandatory”). Box 06-D total equals field 8 and Fields 103 and 104 equal their detail only exist in periods from 01/07/2027. In Mandatory data filled in, the NIF cannot be deleted once there are certified documents (“is already used in certified documents, so its NIF … cannot be changed here”) and, without the company's fiscal region, the product neither calculates nor runs the checks (“Company … has no fiscal region (Mainland/Azores/Madeira)”); that is why only the missing Quadro 04 is shown.

Pending validation by a certified accountant: the description of fields 8, 9, 10, 11, 24, 40, 41, 61, 90 to 96, 103, 104 and 164 and the tax treatment of each check.

Expected result

• In the Checks tab, Blocking checks 0 and the Warnings read and accepted.
• The return can go on to Validate. The checks run again when you validate.
• The result is recorded in the return's chatter: “Checks run by Contabilista (demonstração): 19 result(s), 0 blocking.” (the name is that of the user who ran them).
• This article creates no journal entries: the checks only read.

Important notes

• A warning is not an error. Period closed to VAT appears on every return until you set the VAT lock date. Do it after submitting, not before: closing the period before submitting prevents you from posting anything still missing.
• Drafts count, even small ones. Any draft document dated in the period blocks. A cancelled document does not block.
• The checks only see the period of the return. They do not see documents dated in another period or what is outside Odoo.
• Who changes the rules. The Certified accountant sees, only in developer mode, Accounting › Configure › Checks before submitting (and Declare › Declaration checks). The Accountant does not have these menus, not even in developer mode. The list has one line per return (Periodic VAT return, Modelo 10 and IES); when you open one, each check has a Check code, Severity (in the DP IVA the starting value is As the check decides; in Modelo 10, Always a warning), How to fix (company text) and Active. Changing a severity or turning off a check was not tried.

Common problems

“The return … cannot go on: 1 blocking check(s)”

• Symptom: when you click Validate or Record submission, the screen refuses and lists what is blocking.
• Cause: there is at least one check with Blocking (for example, drafts in the period).
• What to do: in the Checks tab, click Run checks, resolve each Blocking result using the Documents to fix column and the message, and use Calculate again. Full examples in periodic VAT return, under “Common problems”.

The tab shows nothing

• Symptom: you open Checks and the table is empty, with only the Run checks button.
• Cause: the checks have not been run for this return yet.
• What to do: click Run checks.