- The most critical phase of a tender is not finding it, but the supplementary request shortly before award.
- Contracting authorities often only demand complete evidence for promising bids – with deadlines of sometimes just one to two days (Section 56 VgV).
- Anyone who first has to gather references, subcontractor suitability and master-data evidence risks the contract they thought was already secured.
- Centrally available company knowledge cuts the time for complete resubmission from around two days to under one hour.
Shortly before award, it is decided whether a bid ultimately counts. It is in exactly this phase that many mid-sized bidders lose contracts – not to the competition, but to a Request for missing documents in tenders, which is not met in time. This article explains what a supplementary request is, why the deadline becomes a risk and how to avoid it.
What a supplementary request in a tender is
Since the procedural acceleration, a self-declaration is often sufficient in the first step. The contracting authority only demands the complete evidence – references, certificates, suitability of subcontractors – when a bid makes the shortlist. This is legally governed by Section 56 VgV: missing or incomplete documents may be requested, within a set deadline.
That sounds accommodating, but in practice it is a test of time. The deadline is short and comes exactly when the work seems done.
Why the supplementary-request deadline becomes a trap
The deadline for a supplementary request is often one to two days. Anyone who doesn’t have the required documents to hand has to search: which reference fits, is it current, is the subcontractor suitability evidence still valid, where is the latest creditworthiness certificate?
A real-world example: a mid-sized company misses a €1.8m contract – not because of price, but because a single suitability document wasn’t available in time. The bid was the most economically advantageous. It still didn’t count.
The cause is rarely a lack of knowledge, but fragmentation: the documents are scattered across SharePoint, the ERP, old bids and individual employees. If the request for missing documents lands in a holiday week, a two-day deadline quickly becomes a total write-off.
The three most common triggers for requests for missing documents
In most cases it comes down to the same three points:
1. References. A comparable reference from the last three to five years is required – often with concrete figures (contract value, scope of services). Without documentation, it has to be reconstructed under time pressure.
2. Subcontractor suitability. If subcontractors are involved, their suitability must be proven – commitment declaration, certificates, sometimes their own references. This depends on third parties, and third parties rarely respond within 24 hours.
3. Master data and compliance documents. Certificate of good standing, professional liability insurance, entry in the competition register, collective wage compliance declaration. Trivial individually, a problem together under a deadline.
Even before a possible request for missing documents, the go/no-go assessmentdecides whether the effort is worthwhile – and precisely Bidder questions determines how clearly the requirements are formulated in the first place.
The overview of how suitability documents and mandatory fields can be filled in automatically from your own company knowledge is available under automatically filling in tenders.
How to submit missing documents in hours instead of days
The solution isn’t another folder, but centrally searchable company knowledge. When references, certificates and master data are stored in one place and machine-searchable, responding to a request becomes a formality.
This is where AI-powered tender platforms come in: documents and master data are held centrally, and when a request for missing documents arrives, up to 80% of fields can be filled in automatically from existing bids, contracts and references. A complete submission is possible in under an hour instead of two days. Industry-specific trained models take into account that a street-sweeper tender requires different documents than a landscaping contract. aiconver works on this principle.
| Manual today | With central company knowledge | |
|---|---|---|
| Finding documents | Folders, ERP, follow-up queries | centrally searchable |
| Filling in fields | Copy-paste from old bids | up to 80% automatic |
| Time to completion | ~2 days | under 1 hour |
| Risk of missing the deadline | high | low |
Checklist: ready for missing-document requests before submission
Rather than reacting only once the deadline is running, preparation is recommended:
- Keep the reference list up to date, with volume and period, available at any time.
- Obtain subcontractor declarations and documents before submission.
- Store compliance documents (good standing, liability insurance, competition register, collective wage compliance) centrally.
- Name one responsible person per tender – including a deputy for holiday periods.
- Keep all documents centrally and searchably available, not in individual folders.
Those who spot relevant tenders early gain a buffer for exactly this preparation – for example through multi-source aggregation when finding tenders.
Frequently asked questions about requests for missing documents
What is a request for missing documents in a tender?
The contracting authority requests missing or incomplete documents – usually suitability documents, once a bid makes the shortlist. The legal basis is § 56 VgV. A set, often short deadline applies to the submission.
How long is the deadline for a request for missing documents?
The contracting authority sets the deadline. In practice, one to two days is common. If the deadline is missed, the bid can be excluded – even if it was the most economically advantageous.
Which documents are most frequently requested?
References, proof of subcontractor suitability, and master data and compliance documents such as a certificate of good standing, professional liability insurance and a competition register entry.
Can AI help with filling in requested documents?
Yes. Such systems access the company’s own knowledge and fill in fields from it. With providers such as aiconver, this is done in a GDPR-compliant way on German infrastructure, without passing data on to external AI providers.
Conclusion
The request for missing documents is the silent cause of losses in bid management: the contract is practically won and lost over a two-day deadline. The problem is not missing knowledge, but scattered knowledge. Those who keep references, subcontractor documents and master data centrally and searchably deliver a Request for missing documents in tenders completely in under an hour – instead of searching for two days.
aiconver GmbH – AI platform for tenders in manufacturing SMEs.