Introduction
Work experience certificates in Turkish public procurement tenders are among the most decisive qualification documents for bidders. In many public tenders, especially construction works, service procurement, technical maintenance, consultancy-related procurements, infrastructure projects, software services, medical support services and complex goods supply tenders, a bidder’s ability to participate or remain in evaluation depends on whether it can prove sufficient previous experience in the same or similar works.
Public procurement in Turkey is mainly governed by Public Procurement Law No. 4734. Under Article 10 of Law No. 4734, contracting authorities may request information and documents to evaluate the economic, financial, professional and technical qualifications of tenderers. The official English translation of Article 10 expressly refers to documents proving experience in the subject matter of the procurement or similar works performed under contracts in the public or private sector.
For bidders, work experience certificates are not ordinary reference letters. They are formal procurement documents. A company may have strong commercial experience but still be excluded from a tender if its work experience document does not match the tender’s similar work definition, does not prove the required amount, is not issued by the correct authority, is not updated correctly, is not submitted in the required form, or does not comply with EKAP and document presentation rules.
This article explains the role of work experience certificates in Turkish public procurement tenders, including their legal basis, similar work criteria, construction, service and goods procurement issues, foreign work experience documents, EKAP registration, common rejection grounds, complaint and appeal remedies, and practical legal checklists for Turkish and foreign bidders.
What Is a Work Experience Certificate?
A work experience certificate is a formal document proving that a bidder has performed a previous contract relevant to the subject matter of the public tender. It may show that the bidder completed a construction work, delivered goods, performed a service, supervised a work, managed a project or performed a contract accepted by the employer.
The purpose of the work experience certificate is to prove professional and technical capacity. Public authorities do not want to award complex contracts to companies that have no proven ability to perform similar obligations. For example, a municipality procuring a road construction project may require previous road construction experience. A hospital procuring technical maintenance services may require experience in similar maintenance contracts. A public institution buying sophisticated equipment may require evidence of previous supply and installation experience.
Work experience certificates therefore function as a risk-control mechanism. They protect public authorities against inexperienced contractors and protect fair competition by applying the same qualification rules to all bidders.
Legal Basis Under Public Procurement Law No. 4734
The legal foundation is Article 10 of Law No. 4734. This provision allows contracting authorities to request documents for evaluating economic, financial, professional and technical qualifications. For professional and technical qualification, Article 10 includes documents proving experience in works related to the subject matter of the procurement or similar works undertaken by the tenderer under a contract in the public or private sector.
The same article refers, for works contracts, to experience documents relating to works whose preliminary acceptance proceedings have been completed and, for services connected to construction works, to services whose acceptance proceedings have been completed within the relevant statutory period.
This legal framework means that work experience is not optional if the tender documents require it. The administrative specification and tender notice must be reviewed to determine whether a work experience certificate is required, what amount is required, what type of work is considered similar, and which documents will be accepted.
Work Experience as a Qualification Criterion
Work experience is usually a pass/fail qualification criterion. If the bidder cannot prove the required experience, its offer may be excluded from evaluation regardless of price. This is particularly important because a bidder may have the lowest price but still lose the tender due to insufficient work experience.
The required experience amount is normally calculated in relation to the tender price or estimated contract value, depending on the tender type and applicable regulation. The administrative specification will identify the required minimum experience and the similar work definition.
The bidder should not assume that every previous project will qualify. The key question is whether the previous work is legally considered similar to the tender subject. Commercial similarity is not always enough. The tender documents and applicable implementation regulation determine the standard.
Similar Work Criteria
The concept of “similar work” is central in public procurement tenders. A work experience certificate may be valid in form but still insufficient if the documented work is not similar to the tender subject.
For example, a company that completed a general building renovation may not automatically satisfy a tender requiring specialized hospital construction experience. A software company that provided ordinary licensing support may not satisfy a tender requiring cybersecurity operation experience. A supplier that delivered standard office equipment may not satisfy a tender requiring supply, installation and commissioning of laboratory systems.
The similar work definition should be objective, proportionate and connected to the subject matter of the tender. If the definition is unnecessarily narrow, it may restrict competition. If it is too broad, it may fail to protect the public authority’s need for technical capacity.
Bidders should review the similar work clause immediately after obtaining the tender documents. If the similar work definition is unlawful, restrictive or discriminatory, the bidder may need to file a complaint before the tender deadline.
Work Experience Certificates in Construction Tenders
Construction tenders are the area where work experience certificates are most important. Public construction works may involve roads, bridges, hospitals, schools, public buildings, infrastructure, water systems, energy facilities, restoration works, reinforcement works and other public works.
Construction tenders often require substantial previous experience because the risks are high. Delay, poor workmanship, technical defects, site management failures and financial instability may seriously affect public projects.
Work experience in construction may be proven through documents relating to completed works, ongoing works meeting legal thresholds, work supervision, work management or other experience categories recognized under the Construction Works Tender Implementation Regulation. The exact acceptable document type depends on the tender documents and applicable regulation.
The Public Procurement Authority’s official legislation page lists the current Construction Works Tender Implementation Regulation and related construction-specific rules, including current versions and amendments concerning work experience documents.
For contractors, the work experience review must be completed before pricing the bid. If the certificate does not match the similar work group or required amount, the bid may be rejected regardless of commercial competitiveness.
2026 Amendments Affecting Construction Work Experience
Construction work experience rules may change over time. The Public Procurement Authority announced that amendments to the Construction Works Tender Implementation Regulation and the communiqué on work experience documents for construction works performed under public-private cooperation projects and licensed works were published in the Official Gazette dated 13 May 2026 and numbered 33252.
The same announcement states that the amendments introduced rules on updating work experience documents for construction works contracted through discounts over unit prices. The update method differs depending on whether public unit prices are published once during the year or published and/or updated more than once during the year.
This is highly relevant for construction contractors. A work experience certificate’s nominal contract amount may not be the amount used in tender evaluation. Updating rules, indices, announcement date, invitation date and the basis of the unit prices may affect whether the bidder meets the required experience threshold.
Therefore, contractors should not rely only on the face value of the certificate. They should calculate the updated certificate amount according to the current legislation and tender documents.
Work Experience in Service Procurement Tenders
Service procurement tenders may also require work experience certificates. These tenders may include cleaning, security, catering, facility management, vehicle rental, software support, maintenance, call centre operation, logistics, technical operation and other service contracts.
In service tenders, the work experience document should show that the bidder has previously performed services similar in nature and scale. A tender for hospital cleaning services may require experience in similar healthcare environments. A tender for data centre maintenance may require technical maintenance experience. A catering tender may require previous meal production and delivery contracts.
Service work experience disputes often arise when the tender’s similar work definition is narrow. For example, if a tender requires experience in a very specific sub-sector even though broader service experience would be sufficient, the clause may restrict competition. Conversely, if the bidder submits experience from a service that is too different from the tender subject, the contracting authority may lawfully reject it.
The Public Procurement Authority’s official legislation resources include the Service Procurement Tenders Implementation Regulation, which forms part of the legal framework for service tender qualification and documents.
Work Experience in Goods Procurement Tenders
Goods procurement tenders do not always require work experience certificates, but they may do so where the procurement is complex, high-value or technically sensitive. Goods tenders may involve medical devices, laboratory systems, vehicles, machinery, software licences, electronic systems, industrial equipment, spare parts or other products requiring proof of prior supply capacity.
In goods procurement, work experience may prove that the supplier has previously delivered similar goods, completed installation, provided training, performed commissioning or fulfilled warranty and after-sales obligations. A simple sale invoice may not always be enough if the tender requires a formal work experience document.
The Public Procurement Authority’s legislation page includes the Goods Procurement Tenders Implementation Regulation among the current regulatory sources for goods tenders.
Suppliers should check whether the tender requires experience in delivery only or in delivery plus installation, maintenance, warranty or technical support. If the previous contract did not include the same obligations, the certificate may not fully match the tender requirement.
Work Completion, Work Status and Other Experience Documents
Depending on the tender type, work experience may be proven through different document types. In construction tenders, common categories include work completion certificates, work status certificates, work supervision certificates and work management certificates. In service and goods procurement, certificates may relate to completed contracts, accepted services or delivered goods.
The legal effect of each certificate type may differ. A work completion certificate usually proves that the work has been completed and accepted. A work status certificate may prove a certain level of ongoing performance. Supervision and management documents may reflect professional responsibility rather than direct contracting performance.
Bidders should not assume that all experience documents are evaluated equally. The tender documents and applicable regulation determine whether the document type is accepted, what percentage or amount is considered, and whether it satisfies the similar work definition.
Public Sector and Private Sector Experience
Article 10 of Law No. 4734 refers to experience in contracts in the public or private sector related to the procurement subject or similar works.
This is important because bidders may rely not only on public contracts but also on private sector contracts where the applicable regulation and tender documents allow it. However, private sector experience may require stricter supporting documents. The bidder may need to prove the contract, acceptance, invoices, payment records, tax documents or other evidence depending on the tender type.
Private sector work experience disputes often involve authenticity, contract amount, completion status and whether the employer’s acceptance is sufficient. The bidder should prepare a complete evidence package before submission.
Work Experience Amount and Updating
Work experience certificates often need to meet a minimum monetary threshold. The certificate value may need to be updated to the date of the tender according to applicable indices and rules.
Updating is especially important in high inflation environments and long-term construction markets. A certificate issued years ago may have a nominal value that is lower than the updated value used for qualification. Conversely, incorrect updating may cause the bidder to believe that it meets the threshold when it does not.
The 2026 amendments announced by the Public Procurement Authority show the importance of updated calculation methods in construction works, especially for unit price-based works contracted through discounts over unit prices.
Before bid submission, bidders should calculate the updated certificate amount and verify that it satisfies the required threshold. This calculation should be preserved in the tender file.
Use of Work Experience by Legal Entities
In Turkish procurement practice, a legal entity may sometimes rely on experience linked to its shareholders, engineers, architects or related persons under specific statutory conditions. Law No. 4734 contains special rules for engineers and architects in works procurements, including recognition of graduation-based experience under certain conditions and use of such experience by legal entities under ownership-related conditions.
These rules are technical and must be applied carefully. A company should not assume that it can freely use the experience of a shareholder, employee, engineer, architect, director or affiliated company. The tender documents, Law No. 4734, implementation regulations and Public Procurement Board practice should be checked.
Misuse of another person’s experience may lead to exclusion and, in serious cases, allegations concerning misleading information or false documents.
Foreign Work Experience Certificates
Foreign companies and Turkish companies with international project experience often rely on work experience certificates issued abroad. These documents may relate to construction, infrastructure, energy, industrial facilities, engineering, services or goods supply performed for foreign public authorities or private employers.
Foreign work experience documents create additional legal risks. They may need apostille, consular legalization, sworn Turkish translation, notarized copies, proof of authority, underlying contract documents, acceptance records and EKAP-related registration depending on the tender and the document type.
The Public Procurement Authority has issued a specific directive on the registration of work experience documents obtained from construction works performed abroad. The directive applies to work experience documents obtained by domestic or foreign real or legal persons from construction works performed abroad under contracts with consideration in the public or private sector, for the purpose of proving compliance with document presentation rules under the Construction Works Tender Implementation Regulation.
EKAP Registration of Foreign Construction Work Experience Documents
For foreign construction work experience documents, EKAP registration may be necessary to prove compliance with document presentation requirements. Under the relevant directive, applications are made by the certificate holder or authorized representative using a request form obtained through EKAP. The application must include the work experience certificate, the underlying contract, acceptance minutes and documents proving legal authority to apply.
The directive also contains detailed rules on translations and document presentation. Where contracts or acceptance records are in a foreign language, translations must be prepared by sworn translators and must include a statement that the translation is faithful to the original document; where translations are made abroad, additional authentication rules may apply.
This is a critical practical point for foreign contractors. The bidder should not wait until the tender deadline to register a foreign work experience document. Registration, translation, authentication and review can take time.
What EKAP Registration Does and Does Not Prove
EKAP registration of a foreign construction work experience document does not mean that the work was actually performed, that the information in the certificate is true, or that the certificate is valid for every tender. The directive expressly states that registration is informational and only shows that the document complies with the document presentation rules; registration does not constitute a presumption that the work was performed, that the information is accurate or that the document is valid.
The same directive also states that registration does not remove the tender commission’s authority to examine and evaluate whether the work experience document satisfies the tender requirements.
This distinction is very important. A foreign bidder may have an EKAP-registered document but still be rejected if the certificate does not meet the similar work criteria, amount requirement, completion condition or other tender-specific requirements.
EKAP and Electronic Procurement
EKAP has become central to public procurement in Turkey. The Public Procurement Authority announced that the Regulation on Conducting Public Procurements in Electronic Environment entered into force for tenders announced on or after 1 August 2025. Under the electronic framework, tender commissions are formed on EKAP, procurement files are recorded on EKAP, approximate cost documents are prepared through EKAP, and electronic administrative specification templates are used.
The Authority’s legislation page also lists e-forms for goods, services, construction works and consultancy tenders, including categories for work experience documents.
For bidders, this means that work experience compliance is increasingly electronic. Documents may need to be entered, verified, uploaded, referenced or evaluated through EKAP. Bidders should preserve EKAP records, submission confirmations and notification dates.
Common Reasons for Rejection of Work Experience Certificates
Work experience certificates may be rejected for many reasons.
The first common reason is lack of similarity. The documented work may not match the similar work definition in the administrative specification.
The second reason is insufficient amount. Even if the work is similar, the certificate value may be below the required threshold after updating.
The third reason is wrong document type. A bidder may submit a reference letter instead of an acceptable work experience certificate.
The fourth reason is lack of acceptance or completion evidence. The previous work may not have reached the stage required by the tender rules.
The fifth reason is defective presentation. Missing apostille, defective translation, uncertified copy, unsigned document or lack of proof of authority may cause rejection.
The sixth reason is inconsistency. The certificate, contract, invoice, acceptance minutes and translation may contain different dates, amounts, titles or project descriptions.
The seventh reason is improper use of another person’s or entity’s experience.
The eighth reason is lack of EKAP registration where required.
Work Experience and False Documents
Submitting false, misleading or manipulated work experience documents creates serious risk. Under Law No. 4734, tenderers who fail to submit required information and documents or who are found to have submitted misleading information or false documents may face exclusion-related consequences. Article 10 lists failure to submit required information/documents or submission of misleading information or false documents among ineligibility-related issues.
False document allegations may also lead to prohibited act and debarment consequences depending on the circumstances. Therefore, bidders should verify every work experience certificate before submission. This includes checking employer identity, signature authority, contract amount, acceptance records, translation accuracy, project name and date consistency.
Foreign bidders should be especially careful because translation errors may be interpreted as inconsistencies. A poor translation may create unnecessary suspicion even where the original document is genuine.
Challenging Rejection of a Work Experience Certificate
If a contracting authority rejects a work experience certificate, the bidder may use complaint and appeal mechanisms under Law No. 4734. The first step is generally a complaint before the contracting authority. If the complaint is rejected or not answered within the legal period, the bidder may file an appeal complaint before the Public Procurement Authority.
A strong complaint should focus on the exact rejection reason. If the authority claims lack of similarity, the bidder should compare the documented work with the tender’s similar work definition. If the authority claims insufficient amount, the bidder should provide the correct updating calculation. If the authority claims defective presentation, the bidder should show compliance with document submission rules. If the authority rejects a foreign document, the bidder should explain the legalization, translation and EKAP registration status.
The complaint should be evidence-based. It should attach the certificate, contract, acceptance records, translations, calculation tables and relevant tender clauses.
Challenging Acceptance of a Competitor’s Work Experience Certificate
A bidder may also challenge the acceptance of a competitor’s work experience certificate. This may occur where the winning bidder’s certificate allegedly does not meet the similar work definition, is insufficient in amount, belongs to another entity, lacks required acceptance, or was submitted defectively.
This type of challenge must be specific. A general claim that the competitor lacks experience is not enough. The applicant should identify the probable defect and connect it to the tender documents.
The Public Procurement Authority may examine the tender file within the scope of the applicant’s claims. Therefore, a well-prepared appeal petition should clearly explain why the competitor’s certificate should not have been accepted.
Work Experience in Joint Ventures
Joint ventures frequently rely on work experience certificates of partners. Tender documents and implementation regulations determine which partner must provide what level of experience. In construction tenders, pilot partner and other partner experience rules may be especially important.
A joint venture should decide early which partner’s certificate will be used. If one partner’s certificate is defective, the entire bid may be affected. Foreign partners should also consider whether their foreign work experience documents require EKAP registration, legalization or translation.
Joint venture agreements should be consistent with the tender documents. A partner that is responsible for technical performance should have appropriate experience evidence.
Practical Checklist for Bidders
Before submitting a bid, bidders should follow this checklist:
Review the administrative specification for work experience requirements.
Identify the required amount and similar work definition.
Select the correct work experience certificate.
Verify that the certificate belongs to the bidder or can lawfully be used by the bidder.
Check completion, acceptance or status requirements.
Calculate the updated certificate amount.
Review whether the document type is accepted for the tender.
Check consistency between certificate, contract, invoices, acceptance records and translations.
For foreign documents, complete apostille, legalization, sworn translation and EKAP registration where required.
Preserve all EKAP records.
Prepare a legal explanation in advance if the certificate may be disputed.
File a timely complaint if the tender’s similar work definition is unlawful.
Practical Checklist for Foreign Companies
Foreign companies should apply additional controls:
Determine whether the tender accepts foreign bidders.
Identify whether the foreign work experience document is from public or private sector.
Obtain the underlying contract and acceptance records.
Translate all relevant documents accurately into Turkish.
Check apostille or consular legalization requirements.
Use the EKAP request form for foreign construction work experience registration where applicable.
Do not assume EKAP registration proves substantive validity.
Check whether the certificate meets the tender’s similar work definition.
Calculate updated value according to Turkish rules.
Authorize Turkish counsel early to handle complaint and appeal deadlines.
Common Mistakes by Bidders
The first mistake is assuming that commercial experience is enough. Public procurement requires formal proof.
The second mistake is ignoring similar work criteria. A certificate may be impressive but legally irrelevant.
The third mistake is submitting a document with insufficient updated value.
The fourth mistake is relying on a foreign certificate without proper translation or legalization.
The fifth mistake is assuming that EKAP registration guarantees acceptance.
The sixth mistake is using another company’s experience without a legal basis.
The seventh mistake is failing to object to restrictive similar work definitions before the tender deadline.
The eighth mistake is filing a vague complaint after rejection instead of directly answering the rejection reason.
Legal Remedies and Judicial Review
Work experience disputes may proceed through complaint, appeal and judicial review. If the Public Procurement Authority rejects an appeal, the bidder may file a lawsuit before administrative courts. Final decisions of the Authority concerning complaints are subject to judicial review under Law No. 4734.
In court, the issue is legality. The court may examine whether the Authority and contracting authority correctly interpreted the tender documents, similar work definition, work experience amount, document presentation rules, foreign document requirements and equal treatment principle.
Suspension of execution may be requested where urgent relief is needed, especially if contract signing is imminent.
Why Legal Review Is Important
Work experience certificates are highly technical. They combine procurement law, contract law, document authentication, accounting, construction classification, service similarity, goods supply evidence, EKAP procedures and administrative remedies.
A public procurement lawyer can help bidders review tender documents, assess whether the certificate satisfies requirements, calculate updated values, prepare foreign document packages, challenge restrictive similar work criteria, file complaints, prepare appeal petitions and pursue judicial review.
Legal review is especially important in high-value construction tenders, foreign bidder participation, joint ventures, public-private partnership experience, licensed works, service tenders with narrow similar work definitions and goods tenders requiring supply-plus-installation experience.
Frequently Asked Questions
What is a work experience certificate in Turkish public procurement?
A work experience certificate is a formal document proving that the bidder has previously performed a contract related to the tender subject or similar works. It is used to evaluate professional and technical qualification under Law No. 4734.
Is work experience always required?
No. It depends on the tender type and tender documents. However, in many construction, service and complex goods procurement tenders, work experience is a mandatory qualification criterion.
Can private sector experience be used?
Yes, where permitted by the tender documents and applicable regulation. Article 10 refers to experience in contracts in the public or private sector related to the procurement subject or similar works.
Can foreign work experience certificates be used?
Yes, but they may require legalization, sworn Turkish translation, supporting documents and EKAP registration where applicable. The Public Procurement Authority has a specific directive on EKAP registration of foreign construction work experience documents for document presentation compliance.
Does EKAP registration prove that the foreign work was actually performed?
No. The directive states that EKAP registration is informational and only shows compliance with document presentation rules. It does not prove that the work was performed, that the information is correct or that the certificate is substantively valid.
What can a bidder do if its work experience certificate is rejected?
The bidder may file a complaint before the contracting authority and, if necessary, an appeal complaint before the Public Procurement Authority. Final Authority decisions may be challenged before administrative courts.
Conclusion
Work experience certificates in Turkish public procurement tenders are decisive qualification documents. They prove that a bidder has the professional and technical capacity to perform the contract. However, their legal evaluation is formal, technical and tender-specific.
A valid work experience certificate must satisfy the tender’s similar work definition, required amount, document type, completion or acceptance condition, presentation rules and, where applicable, EKAP requirements. Foreign documents require additional attention because translation, legalization, supporting contracts, acceptance records and EKAP registration may be necessary.
The most important practical lesson is early review. Bidders should not wait until bid submission to check whether their certificate is sufficient. They should review the administrative specification, similar work definition, certificate amount, updating method, document presentation rules and EKAP requirements immediately after obtaining the tender documents.
For foreign companies, work experience planning is even more important. International project references can be valuable, but they must be converted into legally acceptable procurement evidence under Turkish rules.
For Turkish and foreign bidders alike, work experience certificates can determine whether a bid is evaluated at all. A strong certificate can open the door to a public tender. A defective certificate can close it before price competition begins. Proper legal preparation, accurate documentation and timely use of complaint and appeal remedies are therefore essential in Turkey’s public procurement market.
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