Which IRPF withholding scale does the calculator use?

The calculator uses Tabla 2 from the AEAT Algoritmo Retenciones 2026 (PDF published 10 September 2026). This is the combined state and autonomic withholding scale used by employers for payroll. It is not the same as the state-only tariff used for the annual IRPF return.

What is the Art. 20 reduction and who benefits from it?

Article 20 of the LIRPF provides a reduction for earned income (rendimientos del trabajo). In 2026 the maximum reduction is 7,302 EUR, available in full when net earned income (after SS contributions) is 14,852 EUR or less. It phases to zero at 19,747.50 EUR. Workers earning above 19,747.50 EUR (before the 2,000 EUR general expense deduction) receive no reduction.

Does the calculator model the solidarity surcharge on salaries above the base maxima?

No. The cotización adicional de solidaridad only applies to salary above the base máxima (5,101.20 EUR/month). For salaries within the ordinary base range, SS contributions are capped at the base máxima and the solidarity surcharge does not apply.

Spain Methodology 2026

Model

Annual gross salary for a contrato indefinido employee in the régimen general (private sector), cotisation groups 4 to 11 (general employees), soltero without children or disability. The calculator computes employee Social Security contributions and IRPF annual withholding, then derives the net annual and monthly salary. Employer contributions are not modelled.

SMI 2026

Concept	Amount	Source
SMI monthly (14 payments)	1,221.00 EUR	RD 126/2026, de 18 de febrero
SMI annual (x14)	17,094.00 EUR	RD 126/2026
Increase vs 2025	+3.1%	Was 1,184 EUR/month

Social Security employee contributions (cotizaciones 2026)

Source: BOE Orden PJC/297/2026, de 30 de marzo (BOE-A-2026-7296).

Concepto	Tipo trabajador
Contingencias comunes	4.70%
Desempleo (contrato indefinido)	1.55%
Formación profesional	0.10%
MEI (Mecanismo de Equidad Intergeneracional)	0.15%
Total (indefinido)	6.50%

The MEI rate increased from 0.13% in 2025 to 0.15% in 2026 (scheduled annual increases until 2030). FOGASA is employer-only (employee rate 0.00%).

Base de cotización limits (monthly, 2026)

Limit	Monthly	Annual
Base máxima (all groups)	5,101.20 EUR	61,214.40 EUR
Base mínima, Group 1	1,989.30 EUR	23,871.60 EUR
Base mínima, Groups 4-11	1,424.40 EUR	17,092.80 EUR

The calculator clamps the monthly cotisation base to the groups 4-11 minimum (1,424.40 EUR) and the maximum (5,101.20 EUR). Salaries above the maximum are still subject to ordinary IRPF on the full gross amount; only the SS base is capped.

IRPF withholding algorithm (AEAT Algoritmo Retenciones 2026)

Source: AEAT Algoritmo Retenciones 2026, PDF published 10 September 2026.

Step 1: Rendimiento neto del trabajo (RNT)

RNT = gross annual minus SS employee contributions (minimum 0).

Step 2: Reducción Art. 20 (RED20)

Updated by RD-Ley 4/2024, maintained for 2026. Let RNT be the figure from Step 1:

RNT (EUR)	Reduction (RED20)
14,852 or less	7,302.00 EUR
14,852 to 17,673.52	7,302.00 minus 1.75 x (RNT minus 14,852.00)
17,673.52 to 19,747.50	2,364.34 minus 1.14 x (RNT minus 17,673.52)
Above 19,747.50	0.00 EUR

Step 3: Gastos deducibles generales

2,000 EUR (Art. 83.3 RIRPF), capped at RNT so the base cannot go negative.

Step 4: Base de retención

Base = max(0, RNT minus gastos generales minus RED20). For a soltero without children no further personal reductions apply.

Step 5: Cuota íntegra (Tabla 2 escala combinada)

Base de retención (EUR)	Cuota acumulada	Tipo marginal
0 to 12,450	0.00	19%
12,450 to 20,200	2,365.50	24%
20,200 to 35,200	4,225.50	30%
35,200 to 60,000	8,725.50	37%
60,000 to 300,000	17,901.50	45%
Above 300,000	125,901.50	47%

This scale (Tabla 2) is unchanged from 2025. It is a combined national withholding scale; the actual IRPF owed in the annual return varies by autonomous community.

Step 6: Mínimo personal credit

Apply the same escala to the mínimo personal (5,550 EUR for a soltero): 5,550 x 19% = 1,054.50 EUR. This amount is subtracted from the cuota íntegra. The result (minimum 0) is the annual IRPF withholding (CUOTA).

Worked example: 30,000 EUR gross

Step	Amount
Gross annual	30,000.00 EUR
Base cotización monthly: clamp(2,500; 1,424.40; 5,101.20)	2,500.00 EUR/month
SS employee: 2,500 x 12 x 6.50%	1,950.00 EUR
RNT: 30,000 minus 1,950	28,050.00 EUR
RED20: RNT above 19,747.50	0.00 EUR
Gastos generales	2,000.00 EUR
Base de retención: 28,050 minus 2,000 minus 0	26,050.00 EUR
Cuota 1: 4,225.50 + (26,050 minus 20,200) x 30%	5,980.50 EUR
Cuota 2 (mínimo personal): 5,550 x 19%	1,054.50 EUR
IRPF (CUOTA): 5,980.50 minus 1,054.50	4,926.00 EUR
Net annual: 30,000 minus 1,950 minus 4,926	23,124.00 EUR
Net monthly	1,927.00 EUR

Not modelled

Employer contributions (empresa side of SS). Personalised IRPF rate (taux personalizado); only the standard withholding from Tabla 2 is implemented. Autonomous community IRPF differences (actual tax on the annual return varies by region). Situación familiar (married, children, disability). Contrato temporal (slightly higher SS rate: 6.55%). Cotización adicional de solidaridad (applies to salary above the base máxima). Pension contributions. SMI exemption from IRPF (SMI-level salaries typically fall below the Tabla 1 exemption threshold of 15,876 EUR for a single person with no children).

Sources

SS cotizaciones 2026: BOE Orden PJC/297/2026 (BOE-A-2026-7296)
IRPF withholding: AEAT Algoritmo Retenciones 2026 (10 September 2026)
SMI 2026: RD 126/2026, de 18 de febrero
Base de cotización limits: BOE Orden PJC/297/2026; Wolters Kluwer bases 2026
Art. 20 reduction: AEAT algorithm PDF, RD-Ley 4/2024

The 30,000 EUR worked example is verified against research/54-spain-payroll-2026.md (section 5), which hand-computes the same result to the cent.

Spain methodology (2026)