Thai-Journal Citation Index: TCI Tiers 1-3

The Thai-Journal Citation Index (TCI) is Thailand’s national citation database and journal-quality classification system. It sorts Thai academic journals into three tiers, re-evaluates them in fixed multi-year rounds, and — because Thai universities and national promotion rules lean on the tier a journal holds — effectively decides which Thai-published article counts as a credential and which does not. If you are assessing a CV from a Thai institution, advising a Thai co-author on where to submit, or checking whether a journal’s “TCI Tier 1” badge is still valid, the tier alone is not the answer. The tier plus the round it was awarded in is the answer.

First: this TCI is Thailand’s, not Taiwan’s

Two different national citation indexes share the acronym TCI, and they are routinely confused in reference lists, CVs and internal review notes.

TCI — Thai-Journal Citation Index (Thailand). The subject of this page. A national index of Thai academic journals, organised into Tier 1 / Tier 2 / Tier 3, tied to Thai academic-promotion practice. Journals are hosted largely on Thai Journals Online (ThaiJO), whose article URLs sit under tci-thaijo.org.
TCI-HSS — Taiwan Citation Index for Humanities and Social Sciences (Taiwan). A different index, in a different country, run by Taiwan’s National Central Library, covering humanities and social-science journals, dissertations and books — and with no tier system of this kind at all. See our separate guide to Taiwan’s TCI-HSS and its TSSCI and THCI components if that is the index you were actually looking for.

The practical consequence: “indexed in TCI” on a Thai CV and “indexed in TCI” on a Taiwanese CV are claims about two unrelated databases. Always resolve which country’s index is meant before you treat the claim as evidence of anything. A quick tell — a Thai TCI claim will normally name a tier; a Taiwanese one will normally name TSSCI or THCI.

What the three TCI tiers actually mean

TCI classifies Thai academic journals into three groups. The definitions circulated consistently by Thai university libraries and by TCI-indexed journals themselves are:

Tier 1 (Group 1) — journals judged to be of high quality, accepted into and included in the TCI database. This is the tier that carries weight in Thai research assessment.
Tier 2 (Group 2) — journals judged to meet the quality bar, accepted into and included in the TCI database. Indexed and legitimate, but a rung below Tier 1.
Tier 3 (Group 3) — journals that did not meet the criteria. Crucially, Tier 3 journals may not be included in the TCI database at all.

That last point is where most misreadings start. Tier 3 is not a lower shelf of the same bookcase — it is closer to “assessed and not certified”. Do not treat a Tier 3 designation as a mild quality signal; treat it as the absence of certification, and go and look at the journal itself.

Note also what the tiers are not. They are not a citation-impact ranking. Unlike Journal Impact Factor quartiles or SJR, a TCI tier is the output of a periodic editorial-and-process audit, not a computed citation metric. A Tier 1 journal is a journal that passed an assessment of how it is run. If you need the citation-metric comparison, see our guides on journal impact factor and quartile rankings and on what journal indexing in DOAJ, Scopus and Web of Science actually certifies.

How a journal reaches Tier 1: the Round 5 (2025–2029) criteria structure

TCI’s fifth evaluation round covers 2025–2029, with certification effective 1 January 2025 to 31 December 2029 — a window stated identically across the acceptance announcements that TCI-indexed journals published after the round concluded.

The scoring architecture for that round, as described in TCI’s own English-language briefing on the 5th-round evaluation (published as an announcement on ThaiJO), works in two parts:

Fundamental (primary) criteria — six of them, all mandatory. A journal seeking Tier 1 “must meet all the fundamental criteria in order to be certified by TCI”. These are pass/fail. Missing one is disqualifying regardless of how well the journal scores elsewhere.
Secondary criteria — nine of them, scored out of 20 points. For Tier 1, a journal “must not only pass all primary criteria but also obtain a total score of 16 points or higher” — that is, ≥ 80% of the available secondary points.

So the Tier 1 bar for Round 5 is a conjunction, not a total: all six fundamental criteria, and at least 16 of 20 secondary points. A journal can be strong on the scored dimension and still fail on a single fundamental one.

The selectivity this produces is real. Figures circulating in Thai journal announcements after Round 5 put Tier 1 certification at roughly 337 of 1,184 assessed journals, about 29%. We were unable to confirm that count against TCI’s own published tables (see the verification note below), so treat it as an indicative order of magnitude rather than an exact figure — but the shape of it, roughly three in ten, is consistent with Tier 1 being a genuinely restrictive designation rather than a default for any journal that applies.

The ethics assessment is deliberately outside the round

This is the detail most English-language summaries miss, and it changes how you should read a tier. TCI also runs an ethics-and-integrity assessment covering journal editors, editorial boards, and the transparent and fair disclosure of Article Processing Charges (APCs). TCI’s own briefing is explicit that this assessment is not part of the criteria for the 5th-round journal evaluation, and that it “is conducted on an ongoing basis whenever complaints arise.”

Two implications for anyone relying on the tier:

A Tier 1 designation is not a statement that TCI has cleared the journal on editorial ethics or APC transparency. Those are handled on a separate, complaint-driven track.
Conversely, an ethics concern can be raised and acted on mid-round, without waiting for the next five-year assessment. The tier list is periodic; the integrity oversight is continuous.

If APC transparency is what you are actually assessing, our guides on APC waiver eligibility by publisher and region and on identifying a predatory journal are the more direct tools.

The re-evaluation cycle, and why a bare tier claim is unusable

TCI re-evaluates on fixed rounds with explicit validity windows. Round 4 ran 2020–2024; Round 5 runs 2025–2029 — a five-year cycle, with each round’s certification expiring at the end of its window.

This is the operationally important part, and it is where administrators get caught:

A tier does not persist between rounds. Tier 1 status awarded for 2020–2024 says nothing about the journal’s status today. It must have been re-certified in Round 5 to still be Tier 1.
Journals move. Both promotions (Tier 2 → Tier 1) and demotions happen at round boundaries. A journal’s own announcements page is often the fastest evidence of which way it went.
Stale badges are common. Journal websites frequently display a “TCI Tier 1” graphic without a validity window. A badge with no round attached is not evidence.

The decision rule: a TCI claim is only usable if it carries a tier and a validity window. “TCI Tier 1” is not a checkable assertion. “TCI Tier 1, Round 5, valid 1 January 2025 – 31 December 2029” is. When a CV, a submission record or a journal homepage gives you the former, go and resolve the latter yourself before you rely on it.

How to check a journal’s current TCI tier

Get the ISSN — both of them. Thai journals commonly hold separate print and online ISSNs, and TCI records are keyed on them. An ISSN search is far more reliable than a title search, particularly where the journal has both a Thai and an English title.
Search TCI’s own journal database at tci-thailand.org. This is the authoritative source for tier and validity window. Do not substitute an aggregator list or a university library’s cached spreadsheet — those go stale at round boundaries, which is exactly when you most need to be right.
Read the validity window, not just the tier. Confirm the record is the Round 5 (2025–2029) certification and not a retained Round 4 entry.
Cross-check the journal’s ThaiJO record. Most TCI-indexed journals publish on Thai Journals Online, under a soNN.tci-thaijo.org or phNN.tci-thaijo.org address. Journals typically post their TCI acceptance announcement there with the effective dates spelled out — useful corroboration, and it is dated.
Match the tier to the publication date of the article you are assessing. If someone published in 2023, the relevant certification is Round 4’s, not Round 5’s. Assessing a 2023 article against today’s tier list is a category error in both directions — it can wrongly credit and wrongly discredit.

Why the tier matters: Thai academic promotion

The reason this question is asked at all is promotion. Academic ranks in Thailand — Assistant Professor, Associate Professor, Professor — are awarded against nationally set criteria rather than being left entirely to each institution. The criteria are issued by the Committee of Civil Servants in Higher Education Institutions (commonly transliterated Kor Por Or / ก.พ.อ.), operating under the Ministry of Higher Education, Science, Research and Innovation (MHESI). Candidates are assessed both internally by their institution and externally by academics elsewhere, which is why promotion standards vary comparatively little between Thai universities.

Published research output is a core component of that assessment, and where an article was published is part of how the output is weighed. This is the mechanism that gives a TCI tier its consequence: for a Thai-published article, the tier is the readily available signal of the venue’s standing.

We are not going to state the exact tier-to-rank mapping, because we could not verify it against the primary regulation. Specifically, we could not confirm from a primary source: which TCI tiers are accepted for which academic rank; how many TCI-indexed publications are required at each rank; how TCI tiers are weighted against Scopus- or Web of Science-indexed publications and their quartiles; or which version of the ก.พ.อ. criteria is currently in force. Secondary sources on this are inconsistent and several describe superseded versions of the regulation, and the governing texts are published in Thai.

What that means for you in practice:

Do not rely on a general rule of thumb here. Confirm the current requirement with the candidate’s own institution — its academic-affairs or human-resources office administers the promotion dossier and works to the version of the criteria actually in force.
Confirm the reference date. Promotion rules in Thailand have been revised more than once; a requirement quoted from a few years ago may describe a superseded regulation.
Expect international indexing to matter alongside TCI. Thai promotion practice also recognises Scopus- and Web of Science-indexed publication, so a TCI tier is one input to the assessment rather than the whole of it.

What we could not verify for this page

In keeping with CASRAI’s sourcing practice, here is what we could not confirm against a primary source when this page was written, so you know which claims to re-check rather than inherit:

The content of the six fundamental and nine secondary criteria. TCI’s English-language briefing states the structure — six mandatory fundamental criteria, nine secondary criteria worth 20 points, ≥16 required for Tier 1 — but does not enumerate the individual criteria. The enumerated list is published by TCI in Thai. Consult tci-thailand.org directly for the full text before relying on any particular criterion.
TCI’s host institution and current funding arrangement. TCI’s own website serves its content through a JavaScript application that our retrieval could not render, so we have not stated a host university or funder here rather than repeat a secondary claim.
The exact Round 5 Tier 1 count (337 of 1,184). Widely repeated in Thai journal announcements; not confirmed against TCI’s published tables.
TCI’s current role in the ASEAN Citation Index (ACI). TCI is associated with the regional ACI initiative, but we did not verify the present governance arrangement and so make no specific claim about it.
The ก.พ.อ. promotion criteria specifics, as set out in the section above.

Where a figure matters to a decision you are making, go to TCI directly. Where a promotion requirement matters, go to the institution.

How TCI compares with other national journal-classification systems

Thailand’s tiering is one instance of a pattern found across research systems that publish substantially in a national language: a domestically governed index that gives locally published scholarship a standardised quality signal, because the international commercial indexes cover it thinly. TCI’s closest structural relatives are the ones that classify rather than merely list:

Qualis Periódicos (Brazil) — CAPES-run stratification of journals into graded strata, used in graduate-programme assessment. The closest analogue to TCI in how directly the classification feeds institutional evaluation.
SINTA (Indonesia) — Indonesia’s Science and Technology Index, which likewise assigns accredited journals to numbered tiers.
HEC Recognised Journals / HJRS (Pakistan) — the Higher Education Commission’s ranked recognition of journals for academic credit.
Publindex (Colombia) — Minciencias’ journal classification, also organised into graded categories on a fixed re-evaluation cycle.
MyCite / MyJurnal (Malaysia) and VJOL (Vietnam) — regional neighbours whose national indexes are primarily indexes; they do not carry TCI’s tiering-plus-promotion linkage in the same form.

The recurring administrative lesson across all of them is the same one this page opened with: these classifications are re-issued on cycles, and a classification quoted without its cycle is not a fact you can act on. It is also worth noting that reliance on venue-based proxies of this kind is precisely what reform frameworks such as CoARA and DORA push against — a TCI tier tells you about the journal, not about the article.

For the Thai research system more broadly, see our guides to the National Research Council of Thailand (NRCT) and its funding role and to NRCT’s Code of Ethics for Researchers and the NECAST framework.

Frequently asked questions

What does TCI Tier 1 mean?

Tier 1 is the Thai-Journal Citation Index’s top classification: a Thai academic journal assessed as high quality, accepted into and included in the TCI database. For Round 5 (2025–2029) it required meeting all six fundamental criteria plus scoring at least 16 of 20 points on the nine secondary criteria. It is an audit of how the journal is run, not a citation-impact ranking.

Is the Thai TCI the same as Taiwan’s TCI?

No. They are unrelated databases in different countries that share an acronym. Thailand’s TCI is the Thai-Journal Citation Index, with the Tier 1/2/3 system described here. Taiwan’s is TCI-HSS, run by Taiwan’s National Central Library for humanities and social sciences, and it has no equivalent tier system.

How often is TCI re-evaluated?

On fixed multi-year rounds. Round 4 covered 2020–2024 and Round 5 covers 2025–2029, so the current cycle is five years. Certification expires with the round — a journal must be re-certified to retain its tier.

Does a TCI Tier 1 journal count for academic promotion in Thailand?

Publication venue is part of Thailand’s nationally set promotion criteria, issued by the Committee of Civil Servants in Higher Education Institutions under MHESI, and a TCI tier is the standard signal for a Thai-published venue. We could not verify the exact tier-to-rank mapping or publication counts against the primary regulation, and Thai promotion practice also weighs Scopus- and Web of Science-indexed output. Confirm the current requirement with the candidate’s institution.

What is the difference between Tier 2 and Tier 3?

Tier 2 journals met the quality criteria and are included in the TCI database. Tier 3 journals did not meet the criteria and may not be included in TCI at all — closer to “assessed, not certified” than to a lower grade of certification.

Where do I look up a journal’s TCI tier?

Search TCI’s own database at tci-thailand.org by ISSN — both the print and online ISSN if the journal has both — and read the validity window alongside the tier. Cross-check the journal’s own ThaiJO page, where acceptance announcements normally state the effective dates.

What is ThaiJO, and how does it relate to TCI?

Thai Journals Online (ThaiJO) is the national platform on which most TCI-indexed Thai journals publish; its article and announcement URLs sit under tci-thaijo.org. It hosts the journals; TCI classifies them. A ThaiJO presence is not itself a tier.

Does TCI Tier 1 mean the journal has been cleared on publication ethics?

No. TCI’s assessment of editors, editorial boards and APC transparency runs separately from the round-based tier evaluation and is complaint-driven and continuous. A Tier 1 designation is not a clearance on those grounds.

TCI (Thai-Journal Citation Index): Tiers, Indexing Criteria and What Tier 1 Means

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