Alvará vs Certificate IMPIC: What's the Difference and When Each Applies

When you look up a construction company on the IMPIC website, the result usually shows one of two designations: alvará (license) or certificate. For most people, the difference is not obvious, and that confusion has real consequences. We have seen property owners hire companies holding only a certificate to perform renovations worth hundreds of thousands of euros, without realising the certificate may not cover that kind of work.

This guide explains what distinguishes the two titles, when each applies, and how to know whether what your contractor holds is enough for the project you have in mind.

What the alvará is

The alvará is the most complete qualification title issued by IMPIC. It allows a company to act as a main contractor, which means being the entity hired directly by the property owner to execute a construction project from start to finish. It is the title required for larger works, and for the majority of relevant-value private and public projects.

Each alvará has three coordinates that define what the company can actually do:

• Class (1 to 9), which caps the maximum value of work the company can take on.
• Categories, which define large work areas like buildings, roads and infrastructure, hydraulic works, installations, and other works.
• Subcategories, which detail the specific work types within each category.

A contractor with class 4 alvará in the buildings category can, in theory, take on a mid-value residential project within the class 4 limit. A company with class 1, on the other hand, is limited to small works and is not even authorized to enter contracts with values above the IMPIC-defined ceiling for that class.

What the certificate is

The certificate is a more limited title. It allows a company to perform smaller works or to act as a subcontractor, without the responsibility or breadth of capabilities required from a main contractor. It is common in companies specialised in specific trades (plumbing, electrical, drywall, painting) or in small businesses that take on low-value projects.

The certificate has its own ceilings, generally tied to lower work values or specific work types. As a rule, it does not allow the company to act as a general contractor on a project above those limits. The company can subcontract that execution to another holding an appropriate alvará, but cannot be the property owner's direct counterparty for a contract that exceeds the certificate's scope.

The most common confusion

The frequent mistake is to assume that "has a certificate" and "has an alvará" are equivalent. They are not. The confusion is understandable, because the IMPIC lookup page presents both title types in a similar interface, and the layperson reads only "active qualification" without decoding whether it is alvará or certificate, what class it has, and what categories it covers.

In practice, this misunderstanding has three predictable consequences:

• Potentially void contracts. If the company's title does not cover the project's scope, the contract may be considered to have been entered with an unauthorized entity, with all that implies in case of dispute.
• Inadequate insurance. The mandatory insurance regime varies by title type and class. A company holding a certificate may have coverages that fall short of the contracted project's scale.
• Diluted technical responsibility. The alvará requires technical directors with qualifications proportional to the class. The certificate has lighter technical requirements, which often shows in execution quality.

When each makes sense

For a property owner, the practical rule is simple. If the work is small and specific (replacing a boiler, redoing the electrical wiring, painting a room, doing the plumbing for a kitchen), a company with a certificate may be perfectly suitable and even preferable on cost. The certificate exists precisely so small companies and specialised trades can operate legally without the burden of a full alvará.

If the project involves coordinating several trades, has meaningful value, or is a significant renovation or new build, what you want is a company with an alvará at the right class and in the right categories. The alvará is not a luxury, it is the indication that the company has the technical, financial, and administrative structure to take on a contract of that size.

There are also hybrid situations. On larger projects, it is common to have a company with an alvará acting as general contractor and several certificate-only companies executing specialised work as subcontractors. In that case, the property owner's contractual relationship is with the general contractor, and it is that company's alvará that matters. Subcontractors answer to the general contractor, not directly to the owner.

How to know which one a company has

The IMPIC public lookup at impic.pt returns, for each company searched, the type of qualification title (alvará or certificate), its number, class or value ceiling, categories and subcategories, and the current status.

The alvará number usually carries a prefix tied to the contracting type (for instance "EOC" for empreitada de obras de construção). The certificate has its own numbering, in a different format. The first thing to look at is, therefore, which of these two labels appears on the result.

Next, and this is the step many people skip, it is worth checking that the classes and subcategories actually cover the specific work you want done. It is not enough that the company has "active qualification". It needs qualification for the right type of work, at the right value.

What IMPIC does not show

The IMPIC lookup only shows what relates to the qualification title. It does not cross-reference court proceedings, tax debts, the directors' situation, or insolvency history. A company can have an active class 6 alvará and at the same time be in insolvency proceedings, or its directors can be linked to companies that recently failed. None of that shows up on the IMPIC lookup.

ObraXRAY cross-references the IMPIC data with 8 other official databases (CITIUS, MJ Publications, tax and Social Security debtor lists, ACT, 197 civil courts, execution registers, and the commercial registry) and runs over 20 automated checks to deliver a consolidated report. The free search shows a visual risk indicator for any Portuguese contractor based on the NIF.

Check a contractor for free on ObraXRAY

Practical summary

• Alvará: for main contractors, projects of meaningful value, with classes 1 to 9 and specific categories.
• Certificate: for small works, specialised trades, or subcontracting, with their own limits.
• Check: type of title, class or limit, categories, subcategories, and status (active, suspended, expired, revoked).
• IMPIC alone is not enough: cross-reference with court proceedings, debts, and the directors' situation.

Read also

• How to Check if a Contractor Has an IMPIC License
• How to Read the IMPIC Lookup Result
• What to Check Before Hiring a Contractor
• How to Verify a Construction Company in Portugal
• How to Choose a Construction Company in Portugal

Note: this article is informational and is based on the applicable legal framework, namely Lei n.º 41/2015 and subsequent legislation. The specific rules for each qualification title can be consulted on the IMPIC website or in Diário da República. For specific cases, consult a lawyer.