How to calculate Italian 13th month net salary tredicesima (EN): the 13th month bonus (tredicesima or gratifica natalizia Christmas gratuity) is the additional monthly salary mandatory for all Italian CCNL collective agreements, paid mid-December. This is a unique Italian feature compared to USA UK Germany France where it doesn't exist by law. The calculator multiplies the gross monthly salary by the worked months ratio (12 months = 100%, 6 months = 50%) and applies taxes: INPS social security employee contribution 9.19% and IRPEF Italian Personal Income Tax with brackets 23%/33%/43% (Budget Law 2026 L. 199/2025) WITHOUT employee deductions (Article 13 TUIR applies only to monthly salary, NOT to 13th). For this reason 13th month is more heavily taxed than ordinary salary, with typical net 60-65% of gross (vs 70-75% of regular salary). Reference frameworks: Agenzia delle Entrate Rome Italian tax agency, INPS Istituto Nazionale Previdenza Sociale Rome national social security, MEF, Italian Ministry of Labour;

Zucchetti Lodi world #1 Italian payroll software, TeamSystem Pesaro, Wolters Kluwer Tax Italy; main CCNLs with mandatory 13th: CCNL Metalmeccanici Federmeccanica Confindustria 1.5M employees payment by December 15, CCNL Commercio Confcommercio 4M by December 20, CCNL Industria Chimica, CCNL Sanita Privata AIOP, CCNL Bancari ABI, CCNL Pubblico Impiego public sector all compartments, CCNL Edili Cassa Edile 13th included in salary monthly accruals; unions CGIL CISL UIL UGL; employer associations Confindustria Confcommercio Confartigianato Confagricoltura. 13th vs 14th: 13th (gratifica natalizia) mandatory for all CCNLs; 14th (gratifica luglio quattordicesima July gratuity) only some CCNLs: Commerce, Banks, Chemical Industry, Insurance. For probation period and termination pro-rata installments due. Maternity: leave months count toward installment accrual (D.Lgs. 151/2001 Maternity Paternity Code). Sickness: 13th accrues regularly within sickness comporto period.

13th month net formula no deductions

Step 1 - Gross 13th = monthly_gross * (worked_months / 12). Example monthly gross 1,500 euro 12 months worked: gross 13th = 1,500*1 = 1,500 euro. Example 6 months worked (hired in July): gross 13th = 1,500*0.5 = 750 euro pro-rata. Step 2 - INPS contribution = gross 13th * 9.19% = 1,500*0.0919 = 137.85 euro. Step 3 - Tax base = gross 13th - INPS = 1,500 - 137.85 = 1,362.15 euro. Step 4 - IRPEF with 2026 brackets (D.Lgs. 216/2023 confirmed L. 199/2025): for cumulative taxable < 28,000 euro IRPEF at 23%; between 28-50k at 33%; above 50k at 43%. WITHOUT deductions (Article 13 TUIR applies only to monthly salary not 13th). Important: 13th is taxed at marginal rate of annual taxable; so if worker's RAL is >28k even small 13th amounts are taxed at 33% or 43% (no reductions). Example employee RAL 30,000 euro 13th 1,500: gross 1,500 - INPS 138 = taxable 1,362; taxation enters 23% to 33% margin; 13th IRPEF ~378 euro; net 13th = 1,500 - 138 - 378 = 984 euro (65.6% of gross). For RAL 50,000 (33% bracket) 13th 1,500 gross - 138 INPS = 1,362 taxable * 33% = 449 IRPEF; net 913 euro (60.9%). For RAL 80,000 (43% bracket) 13th 1,500 - 138 - 586 = 776 (51.7%).

History tredicesima from RDL 1937 to modern CCNLs

The 13th month bonus originated in fascist Italy with Royal Decree-Law 1825/1937 issued by Mussolini for industry employees; the measure codified the practice of some companies paying a Christmas gratuity at year-end to retain employees and reward seniority. The decree introduced an extra mandatory monthly salary in December.

Sectoral extension: after WWII 1946-1960 13th was progressively extended to all sectors: industry workers (CCNL Metalworkers 1948), commerce (CCNL Confcommercio 1950), construction (Cassa Edile 1957 via monthly accruals), public sector (DPR 5/01/1956 Civil Servants Statute), agriculture (CCNL UNAPA 1962).

D.Lgs. 1825/1937 still in force for employees 13th.

14th month (quattordicesima July gratuity) introduced 1960s-70s for commerce (CCNL Confcommercio 1968), banks (CCNL ABI 1971), chemical industry, insurance; remains CCNL-specific optional.

Visentini Tax Reform D.Lgs 597/1973 established separate taxation of 13th without deductions to avoid double tax benefit (deductions already applied on monthly salary).

Payment timing: 13th paid mid-December (by December 15 metalworkers Federmeccanica, by December 20 commerce Confcommercio); some CCNLs provide monthly installments (Cassa Edile 12 monthly accruals).

13th right is non-renounceable by law for all subordinate workers.

Pension contributions: 13th counts toward RAL for INPS pension and other entities; INPS ceiling 122,295 euro 2026 applies to annual contribution base.

Separate taxation: in some cases (e.g. multi-year accrued installments, one-time allowances, union agreements) Article 17 TUIR separate taxation with previous biennium average rate applies.

13th month net table by RAL Italy 2026

5 numerical 13th month examples

Example 1 employee RAL 19,500 monthly gross 1,500 12 months: gross 13th 1,500; INPS 138; taxable 1,362; IRPEF all 23% = 313; net 1,049 (69.9%). CCNL Commercio standard.

Example 2 mid-manager RAL 39,000 monthly 3,000 12 months: gross 13th 3,000; INPS 276; taxable 2,724; in 33% bracket IRPEF 899; net 1,825 (60.8%). CCNL Industria Federmeccanica intermediate.

Example 3 executive RAL 80,000 monthly 6,667 12 months: gross 13th 6,667; INPS 613; taxable 6,054; 43% bracket IRPEF 2,603; net 3,451 (51.8%). Federmanager Previndai profile.

Example 4 new hire July RAL 24,000 monthly 2,000 6 months: gross 13th 1,000 pro-rata; INPS 92; taxable 908; IRPEF 23% 209; net 699 (69.9%). New hire profile Q3.

Example 5 part-time 50% RAL 18,000 monthly 1,500 12 months: gross 13th 1,500; INPS 138; taxable 1,362; IRPEF 23% 313; net 1,049 (69.9%). Part-time CCNL Commercio.

13th month model limitations

Simplified calculation excludes regional and municipal surtaxes (~2-3% taxable to add to net reduction; for RAL 30k Lazio 13th surtaxes ~36 euro). For RAL >56,224 euro 2026 also INPS +1% surcharge (CSI Solidarity Contribution) on excess applies. Performance bonuses tax-detaxed 5% L. 197/2022 up to 3,000 euro for RAL <80k NOT included (bonuses and 13th are separate disbursements). Corporate welfare Article 51 c.2 TUIR (health insurance, employer pension contributions) is separate. Meal vouchers Edenred Sodexo Day up to 8 euro/day are tax-detaxed and excluded from 13th. Fringe benefits 1,000 euro/year tax-free 2024-2026 (Anticipi decree) are in regular paycheck, do not contribute to 13th. Trattamento Integrativo (former Renzi Bonus) for RAL <15k and Cuneo Fiscale supplementary sum 7.1/5.3/4.8% L. 207/2024 are paid in regular monthly paycheck NOT in 13th. Maternity: D.Lgs. 151/2001 Maternity Paternity Code guarantees 13th accrual during mandatory leave (5 months: 2 pre-birth + 3 post or 1 + 4) and optional (6 months). Sickness days accrue 13th within CCNL comporto period (180 days metalworkers, 365 days banks). Strike days do NOT accrue 13th (Cass. SS.UU. 1980/2014). Probation period: pro-rata installments due. Termination: accrued installments paid in TFR Trattamento di Fine Rapporto. Cassa Integrazione Guadagni CIG: in ordinary/extraordinary/COVID 2020-2022 CIG, 13th installments are paid directly by INPS.

Common 13th month errors

Common errors: expecting 13th net equal to monthly net (13th doesn't benefit from Article 13 TUIR deductions and L. 207/2024 Cuneo Fiscale so taxed more heavily, typical net 60-70% vs 70-75% salary); ignoring pro-rata for hires/terminations during year (12 months = 100%, 6 months = 50%); believing accrued vacation reduces 13th (no, vacation handled separately); confusing 13th with discretionary bonus (13th is mandatory by CCNL law, company bonus is discretionary); not considering regional/municipal surtaxes on 13th (~2-3% additional taxable); believing one can renounce 13th for higher monthly net (it's non-renounceable right by law); confusing CCNLs 13th mandatory vs 14th optional (Commerce Banks Chemical Insurance have 14th, Metalworkers Construction Healthcare Public Sector only 13th); expecting 13th on December 25 (legally by mid-December typically 15-20); not considering maternity/sickness (D.Lgs. 151/2001 maternity accrues 13th; sickness within comporto). Marginal taxation: for taxable RAL already over 28k euro 13th is taxed at 33% (vs 23% low RAL worker) or 43% (vs 33% medium RAL); 13th net worsens with rising RAL. Strike: strike days don't accrue 13th (Cassation SS.UU. 1980/2014).

13th month applications Italy

1. Regulatory references: RDL 1825/1937 Mussolini institution 13th employees; CCNL Metalmeccanici Federmeccanica Confindustria 1948 worker extension; CCNL Confcommercio 1950 commerce; D.Lgs. 151/2001 Maternity Paternity; D.Lgs. 216/2023 IRPEF 3 brackets; L. 207/2024 Budget 2025; L. 199/2025 Budget 2026; Article 17 TUIR separate taxation; Article 51 c.2 TUIR corporate welfare; Cassation SS.UU. 1980/2014 strike.
2. Main CCNLs with 13th: Federmeccanica Confindustria Metalworkers 1.5M employees by December 15; Confcommercio Federdistribuzione Commerce 4M by December 20; Industria Chimica AIOP-AIIRA Healthcare; ABI Banks (also 14th July); Public Sector Compartments State Regional Healthcare School; Cassa Edile construction 12 monthly accruals.
3. Payroll software: Zucchetti Lodi HR Zucchetti world #1 Italian, TeamSystem Pesaro, Wolters Kluwer Tax Italy, INAZ TeamSystem; ANCL labour consultants; CNDCEC ODCEC accountants.
4. Special periods: maternity D.Lgs. 151/2001 regular accrual; paternity leave; unpaid leave NO accrual; CIG INPS pays 13th installments; probation from hire date; termination final installments paid in TFR.
5. Unions and employer associations: CGIL CISL UIL UGL major unions; Confindustria Federmeccanica Federchimica Federalimentare; Confcommercio Federdistribuzione FIPE Federalberghi; Confartigianato CNA; Confagricoltura CIA Coldiretti; ABI Banks; ANIA Insurance.

Updated July 2026