If you are self-employed, a professional worker or own your own business, you likely see the tax return submission period as one of those stressful but unavoidable moments in your work life. This includes submitting your VAT return. VAT is an indirect tax paid by consumers. As a businessowner, you only "collect" this tax for the Spanish tax authority. To this end, you need to fill in and submit form 303 for VAT self-assessment to the tax authority.

Consisting of more than 80 boxes for you to fill in, this form is perhaps one the densest to complete but it is of great importance. To make this easier for you, we explain what the form is and how to complete it.

What is form 303?

Form 303 is a quarterly Value-Added Tax return form. Companies must collect VAT on behalf of the tax authority from the buyers of their products or services. Afterwards, they must fill in and file this document and report the invoiced amounts to the tax authority. 

When you buy or sell something, you pay or receive a specific amount for VAT purposes. This tax is applied to end consumers and not businessowners or self-employed workers. For this reason, if you own your own business, you can ask the tax authority to refund you for this payment. Submitting form 303 for quarterly Valued-Added Tax returns will result in you paying the tax authority the difference between the VAT you have included in your sales/services invoices and the VAT you have paid with your expenses. This happens because the additional percentage you include in your invoices as VAT does not belong to you. You are simply the intermediary since you are collecting VAT on behalf of the tax authority. The tax authority will subsequently demand this amount from you by submitting form 303.

This form is divided into eight sections and more than 80 boxes for you to fill in. But don't worry: a lot of them don't need to be filled in and it's simpler than it looks.

Who must submit a quarterly VAT return?

Form 303 must be submitted by any professional, self-employed worker or businessowner who engages in economic activities and operations subject to VAT, irrespective of the type of businessowner they are (company, self-employed, association, cooperative, civil society, etc.) and of the return's result (payable, zero, negative for offsetting or refund). They must all submit form 303 every quarter. This also applies to anyone renting a property or asset and to property developers. Depending on the result of your return, you will either have to pay a given amount to the tax authority or receive an excess from the tax authority.

By the way, as we mentioned above, all self-employed workers or businesses must declare any invoiced tax to the tax authority, even if they have not effectively collected the VAT amount yet. As a consequence, bear in mind that the invoice, particularly its date, must be issued within the period you are submitting the return for.

When do you have to submit form 303?

Most self-employed workers and companies must submit their VAT self-assessment return every quarter (companies with a lot of invoices must do this every month). The tax authority has set the following submission deadlines:

  • First quarter: invoices for January to March. Submission by 20 April.
  • Second  quarter: invoices for April to June. Submission by 20 July.
  • Third  quarter: invoices for July to September. Submission by 20 October.
  • Fourth  quarter: invoices for October to December and annual summary. Submission by 30 January.

Deadlines for online submissions are shorter by five days.

What do you need to complete form 303?

Before you start completing the form, make sure you have a record of all your incomings and outgoings on hand, as well as the respective invoices as proof. Make sure the invoices refer to the right quarter.

How do you fill in form 303?

Now that you know what form 303 is, who must submit it and when, it's time to complete it:

Sections 1 and 2: Identification and Accrual

In section 1, you only need to enter your personal details. In section 2, you need to enter the tax year and period for self-assessment (first quarter, 1T; second quarter, 2T; third quarter, 3T; or fourth quarter, 4T). You are also asked a series of questions about your activity and operations. Choose yes or no, as applicable.

Sección 3: Settlement

The key section in form 303 since this is where you will enter the VAT you have accrued (i.e. collected from your customers), as well as the VAT you have paid to your suppliers. At this point, you need to pay attention since not all expenses can be declared against VAT. Check the tax authority's website for these expenses and their percentage.

This section is divided into two subsections depending on the type of VAT you have selected:


The VAT scheme most often used by self-employed workers. The result is the difference between the settlement of accrued VAT payments minus the total VAT for your expense invoices. To calculate it, you must fill in the following sections:


  • Boxes 01 to 09: you see three rows and three columns. The first column refers to the VAT assessment base, the second to the VAT you apply (4%, 10% or 21%), and the third to the amount you have received as VAT. If you apply different VAT depending on the product or service, you must use a row for each percentage. If you only apply one percentage, fill in one of the rows. If you complete form 303 electronically, the payment is calculated automatically after you enter the first and second fields.
  • Boxes 10 and 11: if you have no intra-community VAT code, you do not need to fill them in. If you have an intra-community VAT code, in box 10 enter the VAT assessment base for the intra-community acquisitions of goods and services completed during the settlement period. The system calculates the payment and displays it in box 11.
  • Boxes 12 and 13: in box 12, enter the VAT assessment bases and payments accrued in the settlement period as investment by the taxable person (i.e. invoices with no VAT which the person receiving the payment must submit a self-assessment return and reflect the tax for).
  • Boxes 14 and 15: during the quarter, you may have issued corrected invoices, failed to make any of your payments, refunded money or made any other change. If that is the case, enter that information in these boxes. Enter the corresponding base and the result when VAT is applied (for refunds, make sure you use the minus symbol, -).
  • Boxes 16 to 26: enter your supplementary VAT charges ("recargo de equivalencias"). Special VAT scheme for the operations of self-employed workers who buy and sell products. The interesting thing is that this section does not apply to self-employed workers, but rather to their suppliers. Consequently, if one or more of your customers fall under this VAT scheme, you must enter the information here. In invoices with 21% VAT, the additional charge must be 5.2%. In invoices with 10% VAT, the charge will be 1.4% and for 4% VAT, the charge is 0.5%. If you make any change to these invoices, as it happened with boxes 14 and 15, you must enter the information in boxes 25 and 26.
  • Box 27: displays the total accrued, i.e. sum of all amounts in the payments column. This is calculated automatically if you file your form online.
  • Boxes 28 and 29: most self-employed workers only need to fill in these two boxes in this block. You must calculate the VAT assessment base for all of your business current expenses (considering the expenses you can declare against VAT) and the resulting VAT payment.
  • Boxes 30 and 31: repeat the calculation above but only if you have purchased long-term assets such as machinery.
  • Boxes 32 to 35: enter purchases from outside the EU that must go through customs and have a DUA invoice, distinguishing investment from current expenses.
  • Boxes 36 to 39: only if you have an intra-community VAT code can you use box 36 to enter the VAT assessment base for purchases within the European Union relating to current and investment expenses.
  • Boxes 40 and 41: used to correct data (like a supplementary return). For example, if you have forgotten to include an invoice or declared too much VAT. Remember that if the corrected result means reducing your deductions, you must use a negative sign.
  • Box 42: enter the payments you have received if you are self-employed under the special agriculture, livestock and fishing scheme.
  • Boxes 43 and 44: if you made any investment before you began operating, such as buying machines, technology or computers, you must declare the corresponding VAT in box 43. If it refers to the fourth quarter, complete box 44 too.
  • Box 45:enter the total amount for deductions.
  • Box 46: Box 27 minus box 45; result of your VAT self-assessment. If the result is positive, you must pay the corresponding amount to the tax authority. If the result is negative, you have paid more VAT than you have collected and you can claim offsetting.


Simplified VAT only applies to self-employed workers who pay taxes based on estimated profits (modules), "estimación objetiva". In fact, if you have stated in the first section of form 303 that you only apply the general VAT scheme, these sections are not shown. If not and you must fill in these sections, you can see the applicable modules indicating the VAT accrued from sales. From this, the system subtracts the VAT that can be deducted for current expenses (not including investments) and adds 1% of the VAT accrued from hard-to-justify expenses.

Additional Information

  • Boxes 59 to 61: section for information purposes only where you must enter sales abroad, which are exempt from VAT.
  • Boxes 62, 63, 74 and 75: "Caja" is a special VAT scheme whereby self-employed workers can defer their VAT payments until they have received their invoiced amounts. These boxes are used to enter the amount under this scheme, both in terms of incomings (62 and 63) and outgoings (74 and 75).

This section shows your return's final result. If you have completed the form online, most of the boxes are filled in automatically.


If box 71 shows a negative result, you can enter the amount here to ask the tax authority to offset it against subsequent returns.

No activity

If you did not engage in any activity during the quarter, you still need to file form 303 albeit blank. This box must be ticked though.


If this is the last quarter of the year and your self-assessment result is negative, you can ask the tax authority to refund the amount to your bank account.


Enter the account number to pay your VAT.


Section for taxpayers who have file a supplementary return. In this case, you must add proof of self-assessment for the return you will be filing.


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