Clarify your doubts by consulting your particular case
The beginning of inspections, either through communication or directly, produces the following effects:
a) Interrupts the legal limitation period (see Chapter 7) to the right of the Administration to determine tax debts, by practicing the appropriate settlements and action to impose sanctions for breach of obligations or duties with respect to tributes to the proceedings relate.
b) Payments made by the taxpayer after the start (via communication or directly) of the proceedings, have the character of mere income in the account of the settlement derived from the record to be instituted. These payments do not prevent the application of appropriate sanctions.
These penalties are calculated on the difference between the amount resulting from that record and the amounts paid before the start of the proceedings.
However, interest on arrears of the amounts paid after the start of the actions is calculated only up until the day before that on which such payment was made.
c) The consultations made by the taxpayer to the tax authorities after the start of the inspection are not included if they try to raise matters on which the inspection is related to.
I had a really urgent problem in the middle of the summer that I needed to get fixed. I tried contacting a bunch of agencies but they were either unavailable, slow, had terrible service or were crazy expensive (one company quoted me 1000€!). Josep replied to me within 10 minutes and managed to submit my forms on the deadline and all for a great price. He saved my life - 100% recommend!