Public Procurement · Sub-area
Preparing Bids for Public Tenders
Most exclusions from public tenders are avoidable. A legally sound bid — with the correct documentation, well-evidenced solvency, and a financial bid calibrated against the abnormally-low threshold — is the difference between being evaluated and being knocked out before the technical envelope is even opened.
Methodology
How we prepare a winning bid
Legal advice on tenders is not limited to reviewing administrative documentation. It covers the entire process, from analysing the tender specifications to the submission receipt.
Analysing the tender specifications
A complete reading of the PCAP and PPT: the contract's subject matter, solvency thresholds, award criteria (subjective and automatic), weightings, tie-break criteria, special execution conditions, and prohibitions on contracting. This stage determines whether it's worth bidding at all.
Structuring the technical bid
Drafting the technical proposal within the tender's limits and aimed at maximising the score on each value-judgment criterion. Checking that it contains no financial references (risk of envelope contamination).
Calculating the financial bid and analysing the abnormally-low threshold
Determining the abnormally-low threshold (the tender's formula or art. 149 LCSP). Analysing whether the optimal bid falls below the threshold and, if so, preparing a feasibility justification with a real cost breakdown.
Evidencing solvency
Verifying that the solvency requirements set out in the tender are available and properly documented: references to executed contracts, turnover figures, current business classification, or external means under art. 75 LCSP.
Submission on platforms
Preparing and submitting on PLACSP, EROD, Vortal, Adquira or the corresponding regional platform. Checking the electronic signature, accepted file formats, maximum document size, and the submission receipt.
The most frequent and avoidable
7 mistakes that exclude bids in public tenders
Experience with TACRC appeals allows us to precisely identify the mistakes that destroy bids from companies perfectly capable of executing the contract. All of them are avoidable with proper preparation.
Incomplete documentation in the administrative envelope
Automatic exclusionOmitting any document required in the tender specifications for envelope A results in exclusion. Correctable defects have a short deadline; non-correctable ones lead to automatic exclusion. Reviewing the tender article by article before submitting is the only safeguard.
Defective or expired electronic signature
Total rejectionThe certificate must be valid at the exact moment of submission and issued in the name of a representative with sufficient evidenced powers. An expired certificate or one issued to a representative without sufficient powers results in the entire bid being rejected, with no possibility of correction.
Financial information in the technical envelope
Exclusion for contaminationPlatforms require separate envelopes (A administrative, B technical, C financial). Any reference to price, discount or cost in the technical envelope — even indirect — is grounds for exclusion due to envelope contamination, under settled TACRC case law.
Poorly evidenced solvency
Exclusion for evidenced insolvencySolvency evidence must correspond exactly to the tender's requirements: references to contracts of the same subject matter, turnover for the accepted financial years, and a current business classification. Incorrect use of external means (art. 75 LCSP) is also a frequent cause of exclusion.
Technical proposal exceeding the tender's limits
Non-scoring / exclusionMany tenders impose strict length limits (pages, font, tables) on the technical proposal. Exceeding these limits results in the excess pages not being scored, or outright exclusion, destroying the technical score regardless of quality.
Abnormally low bid without sufficient justification
Mandatory exclusionA bid that falls below the abnormally-low threshold (tender or art. 149 LCSP) must be accompanied by a detailed and credible justification of how the contract can be executed at that price. A generic justification, without a cost breakdown or proof of real economies of scale, leads to mandatory exclusion.
Last-minute submission with technical issues
Exclusion for latenessSubmitting in the final minutes of the deadline leaves no time to react to platform failures or bottlenecks on electronic portals. Art. 146.3 LCSP only protects technical issues documented before the deadline closes. Without that evidence, the bid is not admitted.
Note: Case law from the TACRC and regional tribunals confirms that these mistakes account for more than 70% of exclusions at the administrative stage. None of them relates to the technical or financial quality of the bid.
Art. 149 LCSP
Abnormally low bids: the most critical part of the financial offer
The decision to bid below the abnormally-low threshold is one of the most strategically delicate calls in a tender. The margin between winning the contract and being excluded can be a matter of a few euros.
Abnormally-low threshold
Set out in the tender specifications or, failing that, calculated under art. 149 LCSP from the average of the admitted bids. In services contracts it is common to set a maximum reduction threshold relative to the base budget or the average.
Obligation to request justification
The Contracting Board is required to request justification from the bidder before excluding them (art. 149.4 LCSP). Without this step, the exclusion is void. The bidder has a minimum of 5 working days to provide justification.
What the justification must include
A detailed breakdown of direct and indirect costs, justification of economies of scale, data on labour conditions and possible subcontracting. A generic justification ("we have lower costs") is insufficient under TACRC case law.
The Board's decision
If the justification is convincing, the bid is admitted. If it is insufficient, exclusion is mandatory. The decision must be reasoned and can be appealed before the TACRC within the general 15-working-day deadline.
Financial bid scenarios
| Scenario | Situation | Consequence |
|---|---|---|
| Above the threshold | Financial bid above the abnormally-low threshold | Admitted with no further steps. Scored according to the tender's formula. |
| Exactly at the threshold | Bid equal to the threshold calculated by the Board | A risk zone: it may fall just inside or outside depending on the Board's rounding. |
| Below the threshold | Bid falls into the abnormally-low category | The Board requests justification. If convincing, it is admitted. If insufficient, exclusion is mandatory. |
| No justification submitted | Bidder does not respond to the justification request | Automatic exclusion. Not appealable on this ground. |
Electronic submission
Main public procurement platforms in Spain
PLACSP
Public Sector Procurement Platform. Mandatory for the central government (AGE) and its instrumental bodies. Manages notices, tender specifications and bid submission for State contracts.
EROD
Bid and Documentation Submission Environment. An electronic submission tool for encrypted envelopes used within PLACSP to guarantee envelope integrity until opening.
Vortal
A platform used by certain public business-sector and semi-public entities. Requires prior registration and a compatible digital certificate.
Adquira
An electronic procurement platform used by some public business-sector entities. Operates with a user certificate and recognised electronic signature.
Regional platforms
Each autonomous community has its own platform: Xunta de Galicia, Catalonia's Public Procurement (EACAT), the Andalusian Regional Government's Procurement Portal, etc. Each has its own formats and requirements.
Related area
Already in the tender and need to appeal?
If you have received an exclusion or an award you consider incorrect, the special TACRC appeal has a 15-working-day deadline and automatically suspends the procedure.
Before submitting
Have a tender deadline coming up? We'll review your bid.
A legal review of your envelopes before submission can prevent exclusion due to formal mistakes that have nothing to do with your company's quality.
Free ConsultationFrequently asked questions about bid preparation
What is an abnormally low bid in public procurement?
A bid is abnormally low when its price is so reduced that it raises reasonable doubts about the ability to execute the contract under those conditions. The threshold is set in the tender specifications or calculated under art. 149 LCSP based on the admitted bids. The Contracting Board must request justification before excluding a bidder. If the justification is insufficient, exclusion is mandatory.
Which platforms are used to submit bids in public tenders?
The main platforms are: PLACSP (mandatory for the central government), EROD (submission of encrypted envelopes), Vortal and Adquira (for semi-public entities), and each region's own platform (Xunta, Generalitat de Catalunya, Junta de Andalucía, etc.). Each platform has its own file formats and electronic signature requirements.
When is it worth using external means to evidence solvency?
External means (art. 75 LCSP) allow solvency to be evidenced by relying on the resources of another group entity or a third party. They are especially useful for SMEs that don't individually meet the thresholds. They require a formal commitment of availability throughout execution and, in certain contracts, joint and several liability of the supporting entity.
Can formal defects in a bid be corrected?
Only partially. Arts. 141-142 LCSP distinguish between correctable defects (usually a 5-10 day deadline) and non-correctable ones that result in automatic exclusion. A missing valid electronic signature at the time of submission, the financial bid already submitted, or the technical proposal cannot be corrected. TACRC case law is restrictive: correction cannot amount to submitting new documentation.
How is the exclusion of a bid challenged?
Exclusion is a procedural act that directly decides the award, appealable through a special appeal in procurement matters (arts. 44-60 LCSP) before the TACRC or the corresponding regional tribunal. The deadline is 15 working days from notification. Filing the appeal automatically suspends the procedure, and the appeal is free of charge.