Analizza Certificazione Unica (CU)

Parse and explain the Certificazione Unica - the employer/INPS income certificate needed to file the Modello 730.

When to activate

Activate when the user:

• Uploads or pastes CU data and asks "Cosa significa questo campo?"
• Asks "Dove trovo il mio reddito sulla CU?"
• Reports that the pre-filled 730 shows different values from their CU
• Has received multiple CUs (e.g., two employers) and needs to reconcile them

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What is the CU?

The Certificazione Unica (formerly CUD) is issued by:

• Datori di lavoro (employers) - for employees
• INPS / enti previdenziali - for pensioners and benefit recipients
• Committenti - for co.co.co. / lavoro autonomo

It must be sent to the Agenzia delle Entrate by 16 March each year, and given to the taxpayer by 31 March.

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Step-by-step instructions

1 - Use Dichiarino MCP (if available)

analizza_certificazione_unica(
  reddito_lavoro_dipendente=35000,
  ritenute_irpef=6800,
  ritenute_addizionale_regionale=350,
  anno=2025
)
→ Returns: summary, quadro_c_values, note, anomalie

2 - Map CU boxes to 730 fields

Use references/CU_CAMPI.md for the complete box mapping.

Key fields to extract:

CU Box	Description	→ 730 field
1	Reddito lavoro dipendente / pensione	→ Quadro C, rigo C1
4	Reddito co.co.co. / assimilati	→ Quadro C, rigo C3
21	Ritenute IRPEF	→ Quadro C, rigo C9 / Quadro F, rigo F2
22	Ritenute IRPEF per redditi co.co.co.	→ Quadro F, rigo F2
23	Addizionale regionale trattenuta	→ Quadro C, rigo C10
24	Addizionale regionale saldo dovuto	→ calculated field
25	Addizionale comunale acconto	→ Quadro C, rigo C11
26	Addizionale comunale saldo	→ Quadro C, rigo C12
43	Acconto cedolare secca	→ Quadro C, rigo C13
101	Contributi previdenziali a carico lavoratore	→ Quadro E, rigo E21
361	Detrazioni per lavoro dipendente applicate	→ verify vs. calculated
362	Detrazioni per familiari a carico applicate	→ verify vs. calculated

3 - Check for anomalies

Flag these automatically:

• Box 1 = 0 but Box 21 > 0 → ritenute senza reddito (unusual)
• Box 361 > expected detrazione lavoro → employer may have over-applied detractions
• Box 1 >> expected for the sector → possible error
• Multiple CUs with overlapping periods → sum redditi, check total ritenute

4 - Summarise for the user

Provide a clear plain-language summary:

📋 La tua CU 2025 - Riepilogo
────────────────────────────
Datore di lavoro: [name if provided]
Reddito percepito:      €35.000,00
IRPEF trattenuta:        €6.800,00
Addiz. regionale:          €350,00
Addiz. comunale acc.:      €120,00

Da inserire nel 730:
• Quadro C, rigo C1:  €35.000
• Quadro C, rigo C9:   €6.800
• Quadro C, rigo C10:    €350

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Multiple CUs (same year, different employers)

If the user has more than one CU:

1. Sum all Box 1 values → single C1 entry
2. Sum all Box 21 values → single C9 entry
3. Attach all CUs to the 730
4. Check that total months ≤ 12 (unless job change mid-year)

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Common questions

"Il mio datore non mi ha dato la CU - cosa faccio?" → The employer is legally required to provide it by 31 March. Contact them first; if unresponsive, file a complaint with the ITL (Ispettorato del Lavoro).

"La CU pre-compila già la mia dichiarazione?" → Yes - the Agenzia delle Entrate receives the CU directly. The 730 precompilato will have Box 1 and Box 21 already filled. Always verify they match your paper CU.

"Ho ricevuto la CU ma sono un dipendente part-time con più datori" → You will have one CU per datore. Sum all C1 values; the 730 precompilato should already aggregate them.