Modelo 145: communicate your data to your payer so they can calculate IRPF withholding

What you need to have to hand

1. DNI/NIE and your full details.
2. NIF and name of your payer (empresa, Seguridad Social or SEPE).
3. Key dates: start of work, births, divorce rulings, recognition of disability.
4. Libro de familia or birth certificates of the children you will declare.
5. Resolution/convenio on custody and maintenance/compensatory pension (if applicable).
6. Disability certificate and, if relevant, reduced mobility certificate.

Documentation

• Modelo 145 completed, signed and dated.
• Libro de familia/certificates to prove descendants (if requested).
• Court rulings or agreements for custody and pensions (if applicable).
• Disability certificates issued by the competent body (if applicable).
• Any proof of cohabitation with ascendants if you include them (they may ask for it to file).

Step by step

1. Go to AEAT and find the form: https://sede.agenciatributaria.gob.es/Sede/retenciones-ingresos-cuenta/modelo-145.html.
2. Download the fillable PDF of Modelo 145. Fill in: your details and NIF, NIF of the payer, family situation, descendants/ascendants, disability and maintenance pensions or annuities (if applicable). Put the dates.
3. Sign and date the form. If your company has an HR portal, upload it; if not, print it and hand it in to RR. HH./payroll.
4. Ask for a stamped copy or download the acknowledgement from the portal and keep it with the supporting documents. This saves you if there’s a dispute.
5. Check the next payslip that the rate has been updated. If not, complain and show the acknowledgement.
6. When something changes (birth, divorce, end of pension, new disability…), submit another 145 within 10 days.

Tricks that save you time

• Give the 145 before payroll closes for the month if you want it to apply immediately. Ask RR. HH. for their cut-off date.
• If they’re withholding too little and you fear a big bill at tax time, ask to increase your withholding voluntarily.
• If your payer is Seguridad Social or SEPE, they usually have an online process to communicate/adjust withholding: use it and save the receipt.
• Check the NIF of the payer and all the dates. One wrong digit and they apply the wrong rate.
• Keep the 145 and supporting documents for at least 4 years (typical inspection period).

Common mistakes that can derail the process

• Assuming it’s filed with Hacienda: it isn’t; it goes to the payer.
• Not signing or not dating the 145: the company won’t apply it.
• Claiming children over 25 or a de facto partner as a dependent spouse: that doesn’t work.
• Forgetting to tick shared custody or not splitting the children 50% with your ex.
• Marking disability boxes without the certificate or geographic mobility without right.
• Not reporting changes within 10 days (births, divorce, end of pensions) and getting the wrong withholding for months.
• Not getting a stamped copy or acknowledgement: if there’s an error you can’t prove you submitted it on time.