Construction Dispute Evidence Checklist

Construction Dispute Evidence Checklist: 14 Items to Prepare Before Suing

In a construction dispute, both sides are convinced they are right — but courts and arbitral tribunals only believe evidence. Many investors and contractors lose cases not because they were wrong, but because they could not keep the paperwork proving they were right: original contracts lost, acceptances agreed only verbally, project emails deleted when staff resigned. The construction dispute evidence checklist below lists 14 categories of documents to collect and organize before filing a lawsuit or an arbitration claim, each with an explanation of why it matters, where to get it, and the traps to avoid. The list works for both court litigation and commercial arbitration.

1. Who this checklist is for and how to use it
2. The detailed checklist
3. Common mistakes when doing this checklist yourself
4. After completing the checklist
5. Frequently asked questions
References

1. Who this checklist is for and how to use it

This checklist is for investors, contractors, general contractors, supervision consultants, and subcontractors — anyone entering or about to enter a dispute related to a construction contract: delays, substandard quality, cost overruns, late payment, or unilateral termination.

The best time to use it is the moment signs of a dispute appear — even from the contract-signing stage. Construction evidence has a "decay" characteristic: site conditions change after remedial work, project staff leave taking their emails with them, site diaries get lost. The earlier you prepare, the more complete your file.

Marking convention: ☐ not done · ☑ done · ⚠ needs lawyer review. For each completed item, note where it is stored (filing cabinet, hard drive, whose email holds it) so you can retrieve it instantly when needed.

2. The detailed checklist

Group A — Contract documents and contract formation

Item 1: Original construction contract and all appendices ☐

What to do: Gather the signed original construction contract with full seals, together with every contract appendix and amendment/supplement documents (if any). Check that each appendix clearly states its number, signing date, and which clause of the original contract it replaces.
Why: The contract is the first and most important basis for determining the parties' rights, obligations, scope of work, contract price, and dispute resolution mechanism. Since 01/07/2026, the legal framework for construction contracts is governed by the Law on Construction 2025 (No. 135/2025/QH15) — Article 80 (general provisions), Article 81 (validity and legal effect), and Article 82 (classification, contents, and contract dossiers) — replacing the Law on Construction 2014, with detailed guidance in Decree No. 210/2026/ND-CP on construction contracts (replacing Decree No. 37/2015/ND-CP). Under Article 81, a valid construction contract serves as the legal basis for the parties to perform and to resolve disputes. Without the original, the other party can deny the signature, the seal, or the contents of the clauses.
How: Compare the signatory's signature against the power of attorney or appointment decision valid at the time of signing; check the overlapping seal across pages; each appendix must be signed and sealed like the main contract.
Watch out: A common trap is scope or unit-price changes agreed only by email or message without a formal appendix. Such agreements may still count as evidence (electronic data is a source of evidence under Article 94(1) of the 2015 Civil Procedure Code), but they are far less persuasive than a formally signed appendix.

Item 2: Contractor selection dossier (for tendered projects) ☐

What to do: Collect the invitation for bids, the winning contractor's bid, minutes of contract negotiation, the decision approving the contractor selection result, and the contract award documents.
Why: The bidding dossier defines the scope of work, technical standards, schedule, and winning price — the baseline for comparison when quantity or unit-price disputes arise. Under the principles for concluding construction contracts in Article 4 of Decree No. 210/2026/ND-CP, the construction contract price is determined on the basis of the winning bid price or the result of contract negotiation between the parties (Clause 1, Article 11 of the same Decree).
How: Ask the investor or bid solicitor for certified copies; if you are the contractor, extract from the bid dossier you submitted.
Watch out: Many disputes arise because the invitation documents describe one thing while the signed contract says another. In that case, the entire negotiation process becomes key evidence clarifying the parties' true intent.

Item 3: Performance security, advance payment guarantee, warranty guarantee ☐

What to do: Gather originals or certified copies of the performance security letter, advance payment refund guarantee, and warranty guarantee issued by banks.
Why: These guarantees evidence the contractor's financial obligations and are the investor's tool for recovering money when the contractor defaults. In a dispute, the issuing bank is often joined as a person with related rights and obligations.
How: Check each guarantee's validity period, extensions (if any), and the payment conditions stated in the guarantee letter (unconditional vs. conditional guarantee).
Watch out: The classic trap is a guarantee expiring without timely extension, or a conditional guarantee whose documentary conditions the demanding party cannot satisfy. Always reconcile the guarantee letter's contents with the contract clauses.

Group B — Construction, acceptance, and quality records

Item 4: Construction site diaries ☐

What to do: Collect the original site diaries prepared by the contractor throughout construction, with confirmation signatures from the supervision consultant or the investor's representative for each day or phase.
Why: Site diaries record day-by-day site developments: labor, machinery, weather, abnormal events such as storms, waiting for site handover, or waiting for materials. They are crucial evidence for proving whether a delay was your fault.
How: Ask the site team to hand over the complete set, check continuity (no unexplained multi-day gaps), and the supervision consultant's confirmation signatures.
Watch out: Diaries prepared unilaterally by one party without the other's confirmation may still be submitted as evidence, but their probative value depends on the court or tribunal's assessment in each specific case. That is why you should get the supervision consultant to sign regularly during construction — not chase signatures after the dispute erupts.

Item 5: Acceptance minutes — work acceptance, phase acceptance, and completion acceptance ☐

What to do: Assemble the complete set of construction work acceptance minutes, phase acceptance minutes (if any), and minutes of acceptance of completed work items or construction works for use.
Why: Acceptance is the legal basis confirming executed quantities and quality, and a precondition for payment. Since 01/07/2026, Decree No. 207/2026/ND-CP detailing quality management, construction execution, and maintenance of construction works (replacing Decree No. 06/2021/ND-CP) applies: Article 22 (acceptance of construction work) requires acceptance to be carried out within no more than 24 hours of receiving the contractor's acceptance request (Clause 3); Article 24 specifies the signatory composition of completion acceptance minutes, including representatives of the investor, the supervision consultant, the construction contractor, and the design contractor (when required).
How: Check that each minutes document carries the signatures of all required signatories, clearly states pass or fail, and includes an appendix of outstanding defects to be fixed (if any).
Watch out: The fatal trap is "verbal acceptance" or acceptance by phone followed by continued construction. In a dispute, the other party denies any acceptance took place, and the contractor has nothing to prove the quantities were done correctly. Every acceptance must be recorded in written minutes.

Item 6: As-built drawings and quality management records ☐

What to do: Collect as-built drawings confirmed by the parties, material test results, quality certificates, certificates of origin for materials and equipment installed in the works, and quality inspection minutes during construction.
Why: When quality is disputed — cracking, settlement, leakage, failure to meet technical standards — quality management records are the evidence showing whether the works were built per the design and with approved materials. Without them, a contractor can hardly rebut allegations of defective or careless work.
How: Ask the testing laboratory for original test result slips; reconcile the actual material types against the material dossier approved by the investor.
Watch out: Many contractors substitute equivalent materials when specified ones are scarce, without written approval. In a quality dispute, that is a fatal weakness.

Item 7: Records of additional quantities — site minutes, variation orders, adjustment approvals ☐

What to do: Gather site confirmation minutes, design change orders, the contractor's variation proposals, and written approvals adjusting the contract price or variation appendices.
Why: Disputes over additional quantities are the most common type in construction. The rule is: without a written approval from the competent person, claiming payment for variations is very difficult, even if the work was actually done.
How: Arrange chronologically for each variation: proposal → site confirmation → approval → execution → acceptance. Each variation is an independent "evidence package."
Watch out: The familiar trap is the investor asking for the work first with "paperwork to follow," then never signing the approval. Practical experience: do not execute variations without at least a written in-principle approval from the competent person.

Group C — Payment and debt records

Item 8: Payment dossiers per installment, invoices, and transfer vouchers ☐

What to do: Collect each installment's payment request from the contractor, quantity confirmation sheets for payment, issued VAT invoices, and all bank transfer slips and payment orders from the investor.
Why: Payment records prove how much of the payment obligation has been performed, how much remains owed, and form the basis for calculating late-payment interest and penalties. In many cases, reconciling payment documents alone determines the disputed amount without complex expert assessment.
How: Reconcile three layers: accepted quantities — requested payment value — amount actually received. Note the reason for any gap at each layer.
Watch out: Keep cash payment vouchers too (receipts, acknowledgments) if any, and make sure the payee signs clearly.

Item 9: Debt reconciliation minutes, quantity and debt confirmation documents ☐

What to do: Collect periodic debt reconciliation minutes, quantity completion confirmations, demand letters and replies, and the debtor's written payment commitments.
Why: A debt reconciliation document signed by both parties is among the most persuasive evidence of the amount still payable. A written payment commitment can also reset the starting point of the limitation period.
How: Each document must state the amount, payment deadline, signature of the authorized person, and seal (if an organization).
Watch out: Never sign a reconciliation before verifying the figures carefully. There have been cases of signing an incorrect debt confirmation and then being unable to prove the right numbers, because the court prioritizes the signed document.

Item 10: Documents on penalties, damages, and warranty guarantees ☐

What to do: Collect delay penalty notices, damage calculation sheets (replacement contractor costs, extended management costs, loan interest), and cost vouchers for defect remediation during the warranty period.
Why: When claiming penalties or damages, the claimant must prove the actual damage and the causal link between the breach and the damage. A damage calculation without supporting cost vouchers is easily rejected.
How: Each claimed damage item must be accompanied by corresponding invoices, vouchers, or outsourcing contracts; separate out costs not yet incurred and note them clearly.
Watch out: Rewards and penalties for breach of a construction contract and compensation for damage must be agreed by the parties in the contract (Article 86 of the Law on Construction 135/2025/QH15); for works under public investment or PPP projects, the penalty may not exceed 12% of the value of the breached portion of the contract (Clause 3, Article 86). When preparing penalty documents, follow the terms agreed in the contract and Article 86.

Group D — Correspondence, notices, and legal events during performance

Item 11: All correspondence — official letters, emails, meeting minutes, messages ☐

What to do: Back up all incoming and outgoing official correspondence, technical and commercial emails, site meeting minutes, and project-related Zalo/Viber/WhatsApp messages.
Why: Electronic data is a source of evidence recognized by law (Article 94(1) of the 2015 Civil Procedure Code). In practice, many change instructions, variation approvals, and delay warnings exist only as emails or messages. Losing them means losing evidence.
How: Export emails as files with full headers (sender, recipient, time); back up messages with account information; keep the original devices for comparison when needed. For important content, have a vi bằng drawn up (see Item 13) or request confirmation in an official written document.
Watch out: A lone screenshot of unclear origin is easily challenged on authenticity. The more systematic and certified your backup, the higher its value.

Item 12: Breach notices, remediation demands, termination documents ☐

What to do: Collect breach notices, written demands for remediation within a deadline, notices of intent to terminate, and termination decisions (if any), together with proof of delivery to the other party (receipts, postal records, read-confirmation emails).
Why: Most construction contracts prescribe a breach-handling sequence: notice → demand for remediation within a deadline → only then termination or sanctions. Skipping the notice step, a party that unilaterally terminates may itself be deemed in breach and liable for counter-damages.
How: Check how many days' notice the contract requires and which delivery forms it accepts; keep proof that the recipient received the document.
Watch out: A common risk is sending notices via a project employee's personal email when the contract does not recognize that form. Always send in the form the contract prescribes, plus additional channels as backup.

Group E — Independent evidence: vi bằng records and expert assessment

Item 13: Bailiff's vi bằng recording the site's actual condition ☐

What to do: Engage a Bailiff Office (Văn phòng Thừa phát lại) to draw up a vi bằng — an official record of facts witnessed in person — recording the site's condition at the time the dispute arises: unfinished quantities, quality defects, machinery and materials remaining on site.
Why: Under Article 36 of Decree No. 08/2020/ND-CP, a vi bằng is a source of evidence for courts when resolving civil cases. In construction disputes, the site changes very quickly after one party leaves or starts remedial work — a vi bằng "freezes" the condition at the time it is drawn up, and carries far greater probative value than self-taken photos.
How: Contact the local Bailiff Office and describe clearly the event to be recorded; the bailiff will personally witness, photograph, film, and draw up the vi bằng, then register it with the Department of Justice as required.
Watch out: A vi bằng does not replace notarized or certified documents (Article 36(2)), and there are cases where a vi bằng may not be drawn up under Article 37 of Decree No. 08/2020/ND-CP. Most importantly: do it as early as possible — a few weeks' delay and the site looks different.

Item 14: Expert assessment conclusions, price appraisal, and legal standing documents ☐

What to do: (a) Prepare a dossier requesting quality assessment of the works or appraisal of the disputed quantities' value; (b) gather the enterprise registration certificate, charter, and powers of attorney of the representative participating in the proceedings; (c) extract the dispute resolution clause from the contract to determine whether the dispute falls under court or commercial arbitration jurisdiction.
Why: An expert assessment conclusion is a source of evidence under Article 94(5) of the 2015 Civil Procedure Code. Parties may ask the court to order an expert assessment, or request one themselves after the court refuses their request (Article 102). In arbitration, the tribunal may also order expert assessments and asset valuation as a basis for resolving the dispute (Article 46 of the 2010 Law on Commercial Arbitration). On jurisdiction: filing in the wrong forum (suing in court when the contract has an arbitration agreement, or vice versa) wastes time and can even cost you the limitation period.
How: Choose an assessment organization with adequate capacity in the construction field; prepare the list of issues to be assessed as specifically as possible (locations, work items, applicable standards). On limitation periods: the limitation for court actions on contract disputes is 03 years (Article 429 of the 2015 Civil Code); for arbitration it is 02 years (Article 33 of the 2010 Law on Commercial Arbitration), unless a specialized law provides otherwise.
Watch out: Do not repair or remediate on your own and only then request an assessment — the assessment object is gone and the conclusion becomes meaningless. If remediation is unavoidable to prevent spreading damage, have a vi bằng record the condition first (combine with Item 13).

3. Common mistakes when doing this checklist yourself

Mistake 1: Keeping only photocopies, losing originals of contracts and acceptance minutes. Photocopies and scans may be accepted in some cases, but when the other party denies them, their probative value drops sharply. Always keep originals in a safe place with backup copies.

Mistake 2: Verbal acceptances, change instructions by phone. Every verbal agreement in construction should be "paperized" right after — in minutes or at least a confirmation email. The habit of written confirmation after each site meeting saves many disputes.

Mistake 3: Emails and messages scattered with departed staff. When project staff leave, work emails and chat groups often "leave" with them. Internal rules should require handover of all project accounts and communication data upon departure, with periodic backups to the company server.

Mistake 4: Delaying the vi bằng until the site has changed. Many parties only think of a vi bằng when preparing to sue — by then the site has been cleaned up or the other side has started remedial work. A vi bằng must be drawn up as soon as the disputed event arises.

Mistake 5: Signing "confirmations" under schedule pressure without recording your position. When asked to sign acceptance minutes or quantity confirmations whose contents you do not agree with, write your position on the minutes (e.g., "signed to confirm attendance at the acceptance session; do not agree with the assessment result"). A signature without reservation is easily read as full agreement.

4. After completing the checklist

Once all 14 items are marked, the next step is to organize evidence around each claim in your statement of claim: payment claims draw on Group C, delay penalty claims on Groups B and D, quality compensation claims on Groups B and E. Each claim should have its own "evidence set" with a summary table listing each document and what it proves.

Items marked ⚠ — especially unilaterally prepared documents, uncertified emails/messages, or cases where court vs. arbitration jurisdiction is unclear — should be carefully reviewed with the lawyer handling the matter before filing. An evidence review session before suing is usually far cheaper than supplementing and fixing evidence mid-case after the case has been accepted.

If you are preparing a file for a construction dispute and need a lawyer to review it and assess the strength of your evidence before filing a lawsuit or arbitration claim, contact FLAT Law Firm — hotline 0988424851.

5. Frequently asked questions

Can I still sue if I have lost the original construction contract?

Yes, you can still file a lawsuit if you retain copies, email correspondence, payment records, and other documents proving that the contractual relationship was actually performed. However, the absence of the original weakens the persuasiveness of your evidence and makes it easier for the other party to deny signatures, seals, or clause contents, so you should gather substitute evidence from the outset.

Are Zalo messages and project emails considered evidence?

Yes. Electronic data is a recognized source of evidence under Article 94(1) of the 2015 Civil Procedure Code. Back them up in full with sender information and timestamps, and keep the original devices for comparison when needed.

Who pays for a construction quality assessment during a dispute?

The party requesting the assessment advances the cost. Once a judgment or award is rendered, the cost is normally allocated according to the outcome — the losing party bears it — unless the parties agree otherwise or the arbitral tribunal allocates it differently (Article 34(3) of the 2010 Law on Commercial Arbitration).

How does submitting evidence in arbitration differ from court litigation?

The general principle is the same: parties have the right and the obligation to provide evidence to prove their claims (Article 46 of the 2010 Law on Commercial Arbitration). The difference is that an arbitral tribunal can order expert assessments and consult specialists more flexibly, and where it cannot collect evidence on its own, it may request court support.

What is the limitation period for suing over a construction contract dispute?

The limitation period for asking a court to resolve a contract dispute is 03 years from the date the person entitled to make the request knows or should have known that their lawful rights and interests were infringed (Article 429 of the 2015 Civil Code). If arbitration is chosen, the limitation period is 02 years under Article 33 of the 2010 Law on Commercial Arbitration, unless a specialized law provides otherwise.

Language versions

References

Civil Procedure Code 2015 (No. 92/2015/QH13), effective 01/7/2016 — Article 93 (evidence), Article 94 (sources of evidence), Article 102 (ordering expert assessment; requesting assessment), Article 103 (ordering assessment of evidence denounced as forged), Article 104 (asset valuation, asset price appraisal).
Law on Construction 2025 (No. 135/2025/QH15), effective 01/07/2026, replacing the Law on Construction 2014 and its amending laws — Article 80 (general provisions on construction contracts), Article 81 (validity and legal effect), Article 82 (classification, contents, and contract dossiers), Article 86 (rewards and penalties for construction contracts, compensation for damage caused by breach, and construction contract dispute resolution).
Decree No. 210/2026/ND-CP of the Government detailing and guiding the implementation of certain articles of the Law on Construction on construction contracts, effective 01/07/2026, replacing Decree No. 37/2015/ND-CP and Decree No. 50/2021/ND-CP — Article 4 (principles for concluding construction contracts), Article 11 (construction contract price).
Decree No. 207/2026/ND-CP of the Government detailing certain articles of the Law on Construction on quality management, construction execution, and maintenance of construction works, effective 01/07/2026, replacing Decree No. 06/2021/ND-CP — Article 22 (acceptance of construction work), Article 24 (acceptance of completed work items and construction works).
Law on Commercial Arbitration 2010 (No. 54/2010/QH12), effective 01/7/2011 — Article 33 (limitation period), Article 34(3) (losing party bears arbitration fees), Article 46 (the arbitral tribunal's authority over evidence collection).
Decree No. 08/2020/ND-CP dated 08/01/2020 on the organization and operation of bailiffs (Thua phat lai), effective 24/02/2020 — Article 36 (authority, scope of drawing up vi bang; legal value of vi bang), Article 37 (cases where a vi bang may not be drawn up).
Civil Code 2015 (No. 91/2015/QH13), effective 01/01/2017 — Article 429 (limitation period for contract actions).