Affidavit of Foreign Law

Affidavit of Foreign Law. When a Thai court or administrative body must apply or take account of the law of another jurisdiction, the standard and often decisive evidence is an affidavit of foreign law: a sworn, expert statement explaining what the foreign law is and how it applies to assumed facts. This is specialist evidence — it proves the legal state of affairs abroad, not disputed facts — and getting it right saves hearings, costs and confusion. Below is a practical, step-by-step playbook you can use immediately: who to appoint, how to structure the affidavit, authentication and translation steps, tactical deployment, timing/cost expectations and a short set of ready-to-use drafting/checklist tools.

Purpose — what the court receives and why it matters

Thai judges are not expected to be experts in other countries’ laws. An affidavit of foreign law:

• identifies the primary legal rules (statutes, regulations) and leading cases in the foreign system;

• explains how courts apply those rules in practice (interpretative lines, exceptions, remedies); and

• applies those legal rules to the assumed facts the tribunal is being asked to accept.

The affidavit does not prove disputed factual matters. If the opposing side contests the affidavit, the court will allow rebuttal evidence or order further proof and may invite oral questioning of the expert.

Who should prepare it — credentials matter

Choose someone who can be produced for questioning and whose credentials are readily verifiable:

• A practicing lawyer admitted in the foreign jurisdiction (best where current practice and case law matter).

• A senior academic with specialized publications (strong where doctrine and comparative analysis matter).

The affiant should set out: admission year, professional position, notable case experience or publications, the databases searched, and a clear statement they are available for cross-examination (video attendance is usually acceptable).

Core structure — make the court’s job easy

Use a short, numbered, modular structure so judges and clerks can find answers quickly:

1. Title & instruction statement — case caption, who instructed the expert and the precise legal questions posed.

2. Qualifications — a short CV and statement of competence.

3. Agreed facts (Annex A) — a clearly numbered bundle of assumed facts the expert relies on. The affidavit must assume, not attempt to prove, contested facts.

4. Legal propositions — short, numbered statements of foreign law with pinpoint citations (statute sections, paragraph numbers of cases). Keep each proposition discrete.

5. Application to assumed facts — concise, reasoned application that cross-references the numbered propositions and exhibits.

6. Sources & research method — list newspapers/databases/official translators, and the cut-off date of the research.

7. Exhibits — full texts of statutes and full judgments relied upon, each with a certified translation.

8. Caveats & conflicting authority — candidly identify major contrary authorities and explain weight.

9. Oath / notarial block — sworn before the competent foreign officer.

Number every paragraph and exhibit; include a short index mapping propositions to the exhibits that support them.

Authentication, legalization & translation — don’t shortcut this

To be admitted in Thailand, follow these steps precisely:

1. Swear/affirm the affidavit in the foreign jurisdiction before a competent officer (notary or court official).

2. Apostille the notarial signature if the foreign country is a Hague member; otherwise obtain consular/legalisation by the foreign ministry and Thai consulate. This authenticates the notary’s authority.

3. Certified Thai translations of the affidavit and every attached foreign authority. The translator should sign a declaration that the translation is accurate; some courts also expect legalisation of the translator’s signature.

4. File originals or certified copies per Thai court/agency rules and retain apostilled originals for inspection.

Missing apostilles or uncertified translations is the most frequent cause of adjournments — start legalisation early.

Exhibits — full texts, not extracts

Always attach the full text of statutes and entire judgments relied upon (not merely excerpts). For unreported decisions include the whole judgment. Where the foreign law has sub-national differences (states/provinces), explicitly identify the territorial scope and include the relevant local authority. Paginate and index exhibits; a short exhibit map (which paragraph relies on which exhibit) is extremely helpful.

Tactical deployment — when and how to use the affidavit

• Early filing: if foreign law is dispositive, file the affidavit with initial pleadings to avoid wasted hearing time.

• Rebuttal planning: expect an opposing affidavit; budget for one rebuttal and potential oral appearance.

• Joint expert or neutral expert: when both parties agree, propose a joint statement or ask the court to appoint a neutral expert — this can be quicker and more persuasive.

• Hearing readiness: instruct the expert to be available for oral questioning (video link is acceptable) and to preserve underlying research files for inspection.

If foreign law is central to the case outcome, secure the affidavit and legalization well before hearing dates.

Timing & likely costs — realistic expectations

• Research & drafting: 1–4 weeks for common jurisdictions; more for obscure systems or complex comparative work.

• Legalization & translation: allow 1–3 weeks (apostille/consular timelines vary).

• Costs: modest affidavits for routine issues may be a few hundred USD; senior experts, extensive research or urgent rush work can be several thousand USD plus translation/legalisation fees. Budget for a rebuttal affidavit and potential oral attendance.

Start early — translation and apostille timelines often drive delay.

Common pitfalls & how to avoid them

• Unsigned opinion letters instead of sworn, apostilled affidavits — weaker and sometimes inadmissible. Always use sworn, properly legalised affidavits.

• Poor translations that change legal meanings — use certified legal translators experienced in both legal systems.

• Blurring law and fact — the expert should assume facts in Annex A; do not ask the expert to decide contested factual questions.

• Unavailable expert — secure a written willingness to attend hearings (video) and a back-up contact.

A pre-execution checklist (below) helps avoid these mistakes.

Sample short affidavit clause (model)

“I, [Name], admitted as an advocate/solicitor in [Jurisdiction] in [Year], of [Firm/University], being duly sworn, say: I have been instructed by [Party] to advise on the law of [Jurisdiction] in relation to the following questions: (1) [Precise legal question 1]; (2) [Precise legal question 2]. The facts set out in Annex A are assumed. My opinion is based on the documents listed in Annex B. Attached as Exhibits 1–N are the primary authorities relied upon. To the best of my knowledge and after the inquiries I describe, the matters contained in this affidavit are true.”

Annex A = agreed facts; Annex B = research documents list.

Ready pre-execution checklist

1. Agree precise legal questions with counsel.

2. Prepare an agreed-facts Annex A or request the court to determine facts to be assumed.

3. Instruct a credentialed foreign lawyer/academic and confirm availability for hearing.

4. Fix research cut-off date and request a research statement.

5. Arrange notarisation and apostille/consular legalisation promptly.

6. Order certified Thai translations and translator declaration.

7. File affidavit with exhibits per tribunal rules and retain originals and apostilles.

Final practical note

An affidavit of foreign law is an expert evidence product: pick a credible author, be laser-clear about questions and assumed facts, attach full primary authorities, authenticate and translate everything properly, and budget for rebuttal and possible oral testimony.