This error may occur when you sign and send a tax return with the result to be entered and it is due to the fact that the NRC is incorrect or does not correspond to the tax return details:
The NRC has been incorrectly filled in.
Check that you have correctly transferred each of the 22 characters of the NRC obtained when making the payment to the declaration.
The CRN consists of 22 alphanumeric characters and generally the first three are the form number to which the entry corresponds (e.g.303…).
The details entered in the tax return do not exactly match those of the payment.
You must access the consultation of the payment made and make sure that the data (NIF, model, amount, year and period) are correct and identical to those included in the declaration.
The period deserves special attention, as it is common to confuse quarterly periods (Q1, Q2, Q3 and Q4) with monthly periods (Q1, Q2, Q3 and Q4):January, 02:February, 03:March, 04:April, etc.).
Also check that the amount paid exactly matches the amount declared (a difference of 1 cent will invalidate the NRC) and check the other related data for possible errors.
If the payment has been made through the payment gateway of the AEAT, you can retrieve the receipt of the operation, with the assigned NRC and all the payment details, from the option "Self-assessments.Consult a previous payment" (by debit payment or card, as appropriate)
If any error is observed in these data, you can contact the corresponding bank directly and request the cancellation of the erroneous NRC, as well as the generation of a new NRC correct in order to be able to file the tax return.
Note: It should be noted that the cancellation of a NRC requires a visit to the bank or savings bank as soon as possible.Otherwise, a "Refund of undue payments" request will be required.