To check a tax return before submission, the accountant must reconcile its figures with accounting data and source documents, verify that all required details have been completed, perform the available form validation, and make sure that the file has been prepared in an acceptable format. For a VAT return exported from 1C, check the file extension separately: it must be xml. Do not submit the return until all identified discrepancies and errors have been resolved.
What to Check in the Tax Return Itself
Start with the general parameters of the return rather than individual amounts. Make sure that the correct taxpayer, reporting period, and type of return have been selected. Check the registration details of the organization or individual entrepreneur, as well as the indicators that affect the composition of the form. If an amended or supplementary return is being filed, its purpose must correspond to the actual circumstances.
Then review the structure of the return. All required sections and appendices must be completed, while unnecessary ones must not contain information transferred accidentally. Pay attention to blank fields, negative values, rounding, and lines with unusually large or, conversely, zero figures. Such values are not necessarily incorrect, but they require additional verification.
After the visual review, reconcile the related lines within the form. The final figures must logically follow from the appendices and detailed breakdowns. If the software performs automatic validation, review every message: a warning may indicate not only an arithmetic error but also a missing or incorrect detail.
Do not specify the number of a legislative article from memory alone. If the check depends on a specific provision applicable in 2026, open the current version of the relevant regulatory legal act and make sure that the provision applies specifically to the required return, period, and taxpayer category.
How to Reconcile the Return with Accounting Records and Documents
Checking a tax return is not limited to clicking the validation button. Its figures must be supported by accounting data. Generate detailed breakdowns for the accounts, registers, and transactions used to compile the form. Compare not only the overall total but also the amounts comprising it.
It is useful to follow this checklist:
reconcile the figures in the return with accounting turnovers and balances;
check the source documents for transactions that affected the return;
identify manual adjustments and determine the basis for each one;
check transactions at the boundary between reporting periods;
make sure that corrected, cancelled, and re-entered documents have been accounted for correctly;
reconcile the final lines with the appendices and internal breakdowns;
check whether any discrepancies arose after the period was closed or documents were reposted.
Pay particular attention to non-standard transactions. A one-off transaction, refund, document correction, or source document received late often requires separate analysis. If an amount in the return differs from the accounting report, first identify the source of the discrepancy instead of adjusting the total manually.
Retain the working breakdowns and the list of checks performed. They will help reconstruct the logic used to complete the form if you need to return to the report later. It is also advisable to record who prepared the return and who performed the review if such a procedure has been adopted by the organization.
Checking the VAT Return File in 1C
When exporting a VAT return from 1C, check the name and extension of the generated file. According to the guidance material, the VAT return file must have the xml extension. A file with a different extension does not meet the specified validation requirement.
The 1C message is quoted verbatim in the material: “The VAT return file must have the xml extension”. It relates to the “Explanations to the VAT Return” document and the return identification procedure. If this message appears, check whether the correct file has been selected and whether its extension was changed when it was saved, renamed, or transferred.
Do not attempt to correct the error simply by replacing the characters after the dot if the file's origin is unknown. First make sure that it is actually an exported tax return file rather than a spreadsheet, archive, printable form, or another document. If necessary, export it again using the standard tools of the configuration in use and repeat the check.
Also make sure that the file relates to the correct taxpayer and period. The xml extension itself confirms only the file format, not the accuracy of the information it contains. Once the file has been generated, do not edit its contents manually without a clear reason: such changes may corrupt the document structure.
What to Do Before Submission
After making corrections, repeat the full validation because changing one document may affect several lines at once. Generate the return again and compare the final figures with the latest version of the accounting data. Make sure that the final file, rather than an earlier copy, has been selected for submission.
Before submission, it is advisable to arrange an independent review based on the “second pair of eyes” principle. The reviewer should receive the return, key breakdowns, and explanations of unusual transactions. If involving a second specialist is not possible, take a break and then go through the checklist again from the beginning.
The submission deadline for a specific return and the applicable provisions should be checked based on its type, reporting period, and the taxpayer's status. The input data does not contain a confirmed deadline or the number of the relevant article, so a universal date cannot be specified. Follow the current official requirements for your particular form and do not postpone the review until the last day.
After submission, retain the final version of the return, the exported file, the acceptance confirmation, and the working breakdowns. Submission itself does not mean that the return has been accepted without comments: check the status received and, if there is an error message, review its contents.
Frequently Asked Questions
Can a tax return be considered checked after automatic validation? — No. Automatic validation helps identify formal and logical errors, but the figures must also be reconciled with accounting records and source documents.
What extension must a VAT return file exported from 1C have? — The provided guidance material specifies the xml extension.
Can I simply rename a file if it has a different extension? — First determine whether it is a valid export of the tax return. It is safer to generate the file again using the standard tools than to change the extension of an unknown document.
What should I do if the total in the tax return does not match the accounting report? — Identify the transaction or document that caused the discrepancy, and check the period and manual adjustments. Do not change the final amount without establishing the reason.
Does the tax return need to be checked again after a correction? — Yes. A correction may change related lines, appendices, and final figures, so the validation must be performed again.