Wrong income
Ask the withholding agent for a corrected CU, which it must send again. In the tax return you enter the correct figure, documented by your payslips.
CAF services · Documents
The Certificazione Unica (CU income certificate)
It is the document almost every tax return starts from. If you know how to read it, you can tell in thirty seconds whether the year will close with a refund or an amount to pay, and why.
01 · The document
What the Certificazione Unica is and who issues it
The Certificazione Unica (CU, the annual income statement) is the document in which the sostituto d'imposta (the withholding agent) states how much it paid you in a year and how much it withheld on your behalf. It gives it to you and sends it to the Agenzia delle Entrate (the Italian Revenue Agency), where it feeds into the pre-filled tax return.
It does not only concern employees: pensioners, contract workers, the self-employed and anyone who has received payments from someone required to apply withholding tax receive one too.
- Your employer, for employment income and similar income.
- INPS (the Italian social security institute), for pensions, NASpI (unemployment benefit), cassa integrazione (wage support), maternity pay and other benefits.
- Clients, for self-employed fees, commissions and occasional work.
- Condominiums, for services they received and certified.
- Social security bodies and pension funds, for the benefits they paid.
If you worked for several employers in the same year, you receive one CU from each. Bring all of them: forgetting one means filing an incomplete return, which data matching almost always brings to light.
02 · The key boxes
The boxes that really matter
The CU is long and most of the boxes do not concern you. These are the ones to look at to see how the year will close.
- The days of tax allowance are the most informative box: they tell you for how many days of the year the employer gave you the allowances.
- If you had two employers and the days add up to more than 365, both applied allowances for the same period: you will owe money at the adjustment.
- The withholdings have already been paid: in the tax return they are subtracted from the tax due.
- The municipal surcharge advance withheld during the year is subtracted from that same year's balance.
- The dependent family members section should be compared with your real situation: if it does not match, the tax return corrects it.
| Item | What it tells you |
|---|---|
| Employment income | The total taxable amount on which the tax is calculated |
| IRPEF withholdings | How much has already been paid on your behalf during the year (IRPEF is Italian personal income tax) |
| Regional and municipal surcharges | Withheld as the balance for the previous year and as an advance for the current one |
| Days of tax allowance | The days for which the employment allowances apply: if there are fewer than 365, you worked only part of the year |
| Allowances for dependants | How much you have already been given in your payslip for family members |
| Deductible expenses and tax credits | Expenses already taken into account by the employer, typically supplementary pension contributions |
| Adjustment | The result of the recalculation made by the employer at the end of the year or when the job ended |
The most frequent case of owing money at the adjustment is someone who changed job mid-year, or received NASpI and then went back to work. Each withholding agent applied the allowances as if it were the only one, and in the tax return the two incomes are added together on a single scale of tax rates.
03 · The deadlines
When you receive it and where to find it
The delivery deadline is set by law and falls in the early part of the year, before the tax return season opens.
From your employer
On paper or electronically, depending on company practice. If your employment has ended, you receive it at the address you gave.
From INPS
You download it from your social security file using SPID or CIE (Italy's digital identity systems), or request it through a CAF (authorised tax assistance centre) with a proxy.
From the cassetto fiscale
Every CU sent in your name can be viewed in your personal area on the Revenue Agency's website (the cassetto fiscale, your online tax file).
In the pre-filled return
The data flows in automatically. If a CU is missing, the income does not appear and the return is incomplete.
If it does not arrive
It is not a reason not to declare.
- Chase the withholding agent in writing: it is required to issue it
- Check in the cassetto fiscale whether it has been sent anyway
- Failing that, you declare on the basis of your payslips
- Failure to deliver it carries a penalty for the withholding agent, not for you
04 · Self-employment
The CU for the self-employed
If you issue invoices subject to withholding tax, you receive a CU specific to self-employment, structured differently from the one for employees.
- It shows the fees paid during the year on a cash basis: what counts is when you were paid, not when you invoiced.
- It states the withholdings made and the payment reason code, which identifies the type of work.
- It shows amounts not subject to withholding, such as documented expense reimbursements.
- Taxpayers under the regime forfettario (the flat-rate scheme) still receive the CU, but with no withholdings, because none is applied to them.
- The total of the CUs you receive does not necessarily match your turnover: invoices not yet paid are not included.
The difference between turnover and certified fees is normal and should be explained, not hidden. Invoices issued in December and paid in January appear in the following year's CU: it is the cash basis that governs self-employment.
05 · Corrections
What to do if it contains mistakes
Mistakes happen and should be reported straight away, because a wrong CU carries through into the pre-filled return and the tax return.
Withholdings do not match
Compare with your payslips. If the CU shows less than was withheld, the difference can still be subtracted if it can be proved.
Wrong dependants
This is not a mistake to correct in the CU: the tax return recalculates the allowances on your real situation.
Wrong days of allowance
It affects the calculation of the employment allowances. Report it to the withholding agent and correct it in the tax return.
CU never sent
The income does not appear in the pre-filled return but still has to be declared: the obligation to declare lies with the person who received it.
Duplicate
Two CUs from the same withholding agent for the same period: check which one is valid; often the second is a correction.
06 · Beyond the tax return
Where you need it besides the 730
The CU is the income document par excellence and is asked for in many situations that have little to do with tax.
- For the ISEE DSU (the self-declaration behind the Italian household financial indicator), when your income is not yet in the databases.
- For benefit applications to INPS that have an income threshold.
- When applying for a mortgage or a loan, together with your latest payslips.
- For renewing your permesso di soggiorno (residence permit), as proof of income.
- For study grant applications and for the university ISEE.
- For the tax return, which remains its main use.
Keep a digital copy together with your December payslip: the CU plus your last payslip covers almost every request for documents that comes up during the year.
Frequently asked
The questions that keep coming up
I worked for two companies. Do I need to bring both CUs?
Yes, all of them. The incomes are added together and the tax is calculated on the total with a single scale of rates, not on each one separately.
This is exactly the case that produces an amount to pay at the adjustment: each employer applied the allowances as if it were the only one. It is not a mistake, but you should allow for it before June.
My former employer will not send it. What do I do?
The withholding agent is required to issue it, and failing to do so carries a penalty for them. The first step is a written reminder, which also serves as proof.
Meanwhile, check in the cassetto fiscale whether it has been sent to the Revenue Agency anyway: the data is often there even when your copy has not arrived. As a last resort, you declare on the basis of your payslips.
I am on the flat-rate scheme. Do I receive a CU?
Yes: clients who are withholding agents also send it for fees paid to people on the flat-rate scheme, showing the amounts with no withholdings.
It does not affect the calculation of the substitute tax, which follows the scheme's own rules. But it is data the Revenue Agency holds, and it has to be consistent with what you declare.
The CU shows less than I invoiced. Is it a mistake?
Almost never. The CU certifies the fees actually paid during the year, while your turnover also includes invoices issued but not yet paid.
Year-end invoices paid in January appear in the following year's CU. The difference is normal and consistent with the cash basis.
Let's talk
Two CUs in the same year almost always mean an amount to pay at the adjustment
Two employers who could not see each other each applied their own tax allowances. It is nobody's mistake, but the bill arrives with the tax return.