How to fill in the Spanish modelo 145: what each box does to your payslip

What form 145 is, and why it is not filed anywhere

Form 145 is how you tell the company that pays you who you are. Your family situation, your children, the parents you support, your degree of disability if one is recognised, the maintenance a court has ordered you to pay, and your home loan if you still hold the right to deduct it.

The company takes those facts, runs the procedure of articles 82 to 88 of the Spanish income-tax Regulation, and gets a number with two decimals. That number is the percentage on your payslip.

One thing is worth fixing at the outset, because most pages leave it implicit: form 145 is not filed with the Agencia Tributaria. Article 88.1 obliges the payer to keep the duly signed communication, and that is where the procedure ends. There is no register, no receipt, no filing deadline in the sense the modelo 303 or the modelo 130 have one. It is a document between you and whoever pays you.

That also explains why the tax office publishes the form but never receives it. Article 88.1 only says that "the content of the communications shall conform to the model approved by Resolution of the Tax Management Department", and the resolution in force is the one of 3 January 2011.

The real order of the form: first, is anything withheld at all

Before any percentage is computed, the system asks a binary question. Article 81 compares your pay for the year with a threshold that depends on two things: your family situation and how many descendants you have.

Three details of that table are often misread.

The first is the cell with no figure. Situation 1 has no zero-descendants column because it is defined as the single-parent household entitled to the reduction of article 84.2.4.º of the Act: without children it does not exist. The tax office's own validation rejects it with an explicit message, "family situation 1 requires the taxpayer to have descendants".

The second is what it is compared against. It is compared against the foreseeable gross pay, the article 83.2 figure, not against the reduced base. Someone on €17,000 gross may have a base of €8,500 and is not exempt: the threshold looks at the gross.

The third is the one almost nobody carries. Paragraph 3 of that same article 81 disapplies the exclusion whenever the minimum rates of article 86.2 govern. On a special dependent employment relationship 15 % is withheld even if the pay is far below the table. The exclusion is not a general right to pay nothing below that figure: it is a rule of the ordinary procedure, and there is a procedure that is not the ordinary one.

From your salary to the base: what comes off, and in what order

If there is withholding, article 82 imposes five successive operations. The first three build the base.

You start from the gross pay of article 83.2: everything you will foreseeably receive in the calendar year, in cash and in kind, fixed and variable. On the variable part the law presumes, as a minimum, last year's figure, unless a lower amount is objectively evidenced.

From that come off, in this order:

1. The irregular-income reductions of articles 18.2 and 18.3 of the Act.
2. Social security contributions and equivalents.
3. The €2,000 of "other expenses" of article 19.2.f), which becomes €4,000 if you were unemployed and moved municipality to take the job, and which rises by a further €3,500 or €7,750 for a person with a disability who is in active work.
4. The reduction for obtaining employment income of article 83.3.d).
5. The €600 for a pensioner, the €600 for someone with more than two descendants and the €1,200 for someone on unemployment benefit, which are compatible with each other.
6. Court-ordered spousal maintenance.

The fourth deserves a note, because it is why the minimum wage is not withheld on. Its three bands are €7,302 up to €14,852 of net income, then a taper of €1.75 per extra euro up to €17,673.52, and then €1.14 per euro up to €19,747.50, where it reaches zero. The tax office's own specification says what it is for: so that an amount at or below the minimum wage is not subject to withholding, and so that income close to it does not suffer "an error de salto", a cliff.

That the three bands meet is not a coincidence, and it can be checked. At €17,673.52 the first band gives 7,302 − 1.75 × 2,821.52 = €2,364.34, exactly the figure the second band starts from. And at €19,747.50 the second gives 2,364.34 − 1.14 × 2,073.98 = €0.0028, i.e. zero to within a third of a cent. The 1.14 was chosen to make it land there.

The personal and family allowance is not subtracted from the base

This is where the procedure parts company with what almost everybody pictures, and it is worth understanding because it changes the real value of every box you are about to tick.

Article 85 applies the scale to the base for computing the rate. Then it applies the same scale to the personal and family allowance. And it subtracts the second figure from the first.

It does not subtract the allowance from the base and then apply the scale. The consequence is concrete: the allowance is always relieved at the rates of the first brackets, starting at 19 %, never at a high earner's marginal rate. A child is worth the same in quota to someone on €25,000 as to someone on €90,000.

The allowance is built from articles 57 to 61 of the Act, and article 84 of the Regulation makes two changes to it that exist only here:

• The payer does not apply rule 2ª of article 61 of the Act, the one that removes the allowance when the child or parent files their own return with income above €1,800. The reason is obvious once you think about it: your employer cannot know. And that is why the percentage on your payslip and the outcome of your annual return are not the same sum, by design rather than by error.
• Descendants count by half, unless the entitlement is exclusive.

The box most people fill in wrongly

The children. And not out of carelessness, but because the rule is counter-intuitive.

If both parents work, each declares the same child to their own employer. If each employer applied the whole allowance, the same child would be relieved twice in the same year. That is why article 84.2.º counts by half, and why the form has a separate box for saying the allowance is exclusively yours.

The amount is assigned by age, oldest first: €2,400 for the first, €2,700 for the second, €4,000 for the third and €4,500 for the fourth and beyond, plus €2,800 for each one under three. The halving applies child by child rather than to the total, so a family where one child is exclusive and another is shared has a mixed calculation.

With ascendants the rule is different, and this genuinely appears in no guide: they are not halved, they are divided by the number of descendants of the same degree who live with them, including you. Three siblings supporting their mother each apply €383.33 of the €1,150 of article 59. Two different rules, on the same form, two boxes apart.

One more detail about the under-threes: the calculation looks at the year of birth, not the exact age. In 2026 that means children born in 2024, 2025 and 2026. A child born in December 2023, who will be two for most of 2026, does not open the increase.

The 43 % that removes the cliff

Just above the article 81 threshold something has to stop the rate going from nothing to a serious figure over one euro of difference.

That something is article 85.3: below €35,200 of gross pay, the withholding quota cannot exceed 43 % of the amount by which the gross exceeds your own exclusion threshold. One euro above the line, the maximum quota is 43 cents and the resulting rate is essentially zero. The percentage climbs from zero continuously.

It performs exactly the same job as the error-de-salto correction of article 22.2 of the Spanish inheritance-tax Act, by a different technique: there the quota is corrected, here it is capped.

Then two operations the rule does not fully explain

The last two live in article 86, but the exact way to do them is in the technical specification the tax office publishes every year for whoever writes payroll software.

The first is the home-loan box. Article 86.1 says the rate "shall be reduced by two whole points". The specification implements it by subtracting 2 % of the gross pay from the quota, truncated, which is the same idea with the rounding done somewhere else. And that box is close to a fossil today: it only reaches people who still hold the main-home investment deduction of transitional provision eighteen, i.e. homes acquired or refurbished before 2013, and only if gross employment income from all of your payers stays below €33,007.20 a year. Article 88.1 says so expressly: with two or more payers the limit is measured on the total. And it is never available where the money goes on building or extending.

The second is the truncation. Article 86.1 only says the rate "shall be expressed with two decimals". The specification is explicit and gives its own example: a rate of 17.85964523 stays at 17.85. It is not rounded. A tool that rounds gives a different number from your payslip.

What happens if you do not hand it in

Article 88.2 answers without ornament: the payer "applies the withholding rate that corresponds without taking those circumstances into account".

That is not "the maximum". It is the calculation for a single person, with no children, no dependent parents and no court-ordered payments, on the €5,550 allowance and nothing more. It almost always produces a higher percentage than your real one, and the excess is refunded when you file, a year later. It is not a penalty; it is an involuntary loan to the tax office.

What happens if you fill it in wrongly

Here the answer is harsher, and it sits outside the income-tax Regulation. Article 205 of the General Tax Act makes it a tax infringement "to fail to communicate data, or to communicate false, incomplete or inexact data, to the payer of income subject to withholding, where this results in withholding lower than that due".

And the scale of the penalty is the interesting part:

• A minor infringement and a fine of 35 % of the difference if you are obliged to file a return that includes that income.
• A very serious infringement and a fine of 150 % of the difference if you are not.

Read that twice, because it runs against the intuition. The same inaccuracy is punished more than four times as heavily for the person who earns least. The legislator's logic is that if you file, the annual return will correct the difference anyway; if you do not file, the withholding was the only chance for that money to arrive, and misreporting closes it.

When you hand it in, and the two speeds of a change

Article 88.3 places the communication before the first day of each calendar year or before the relationship begins, taking the situation that will foreseeably exist on those dates. And it adds the sentence that contradicts the habit of signing one every January: the communication does not need repeating each year while the taxpayer's personal and family circumstances do not change.

What does have to be communicated is the change, and article 88.4 makes that deliberately asymmetric:

• A change producing a lower rate "may be communicated" and takes effect from the date of the communication. Your option, no deadline.
• A change producing a higher rate "must be communicated within ten days of the situation arising". Your duty, with a deadline.

Good news is your right; bad news is your obligation. And the same practical condition weighs on both: they are only taken into account if at least five days remain before the corresponding payslip is prepared. That five-day rule appears three times in article 88 and is what separates a communication that works from one that waits until next month.

When you see it on your payslip: the recalculation

When something changes, the company recomputes the rate under article 87 rather than starting the year again. It computes a new quota with the new circumstances, subtracts what has already been withheld, and divides the remainder over the pay left until December.

Two points almost nobody mentions, and they decide what you will see:

• Who has the initiative depends on the cause. Causes 1 to 4 of article 87.2 (the contract that continues, the unemployment benefit that resumes, a rise or fall in pay, a new pension) apply from the date they happen, because the company knows about them by itself. Causes 5 to 11 (a new child, a parent, a disability that arises, a move of municipality, a court-ordered payment, a spouse who starts earning more than €1,500, the home loan) apply from the moment you communicate them. Those are precisely the ones only you know, and precisely the content of form 145.
• The company may batch them. Article 87.4 lets the payer, at its option, carry out recalculations from 1 April, 1 July or 1 October in respect of changes in the preceding quarters. A child born in May may lawfully not show up on the payslip until July.

And if the new rate comes out at zero, article 87.3.c) is blunt: what has already been withheld is not refunded. You recover it in the annual return, not on the next payslip.

Two more things that are in the rule and not in the guides

You can ask to have more withheld, and it is not reversible in the short term. Article 88.5 lets you request a rate higher than the one the calculation gives, in writing, and obliges the company to comply. What is almost never mentioned is letter b) of that same paragraph: the requested rate applies at least until the end of the year and keeps applying in later years until you renounce it in writing or ask for a higher one. It is a decision with inertia.

What you write is protected. Section ten of the 2011 Resolution recalls it by citing article 95.4 of the General Tax Act: withholders are bound to "the strictest and most complete secrecy" over the data communicated, and breaching that duty is a serious tax infringement under article 204. The company is also obliged to safeguard any documents you attach, such as the copy of the judgment fixing a maintenance payment.

And if you draw a pension, the rate may not be the only problem. Form 145 decides what percentage is withheld from the pension you receive; the second transitional provision decides whether part of that pension should be taxed less, or not at all. Anyone who paid into a mutualidad laboral before 1979 can have one slice of their pension reduced by 100 % and another by 25 %, and that is claimed separately.

A worked example with real numbers

Someone on €30,000 gross a year over fourteen payslips, €1,905 of social security, situation 3 and no children.

Net employment income is €28,095. Take off €2,000 of other expenses; the article 83.3.d) reduction is zero at that income. The base for computing the rate lands at €26,095.

The scale on that base gives €5,994.00. The scale on the €5,550 allowance gives €1,054.50. The quota is the difference: €4,939.50. Over €30,000 of gross that is 16.46 % once truncated, i.e. €4,938.00 a year and €352.71 per payslip.

Now declare one child under three, shared with the other parent. The allowance rises to €8,150, the scale applied to it becomes €1,548.50, and the rate falls to 14.81 %: about €35.35 less on every payslip.

And if that same child were exclusively yours, the allowance would reach €10,750 and the rate 13.17 %. The box you tick is the same; the effect is twice as large. Which is why it is worth knowing which of the two applies to you before you sign.

Where form 145 fits with everything else

It is the piece that was missing from the quarterly envelope we already publish from the other side. The modelo 111 is the form with which your employer pays the tax office, every three months, everything withheld from its workers and from the professionals who invoice it. Form 145 is where your share of that figure comes from.

One is filed by the company with the tax office and the other is handed by you to the company. It is the same money, seen from both ends.