Bitkub review: the IOST/THB market, its fees and its trust problem

Verdict: convenient for baht, hard to trust with savings

If you live in Thailand and want IOST, Bitkub is the obvious first stop. It is the only exchange we found with an IOST order book in Thai baht, it is licensed by Thailand’s Securities and Exchange Commission, and you can fund it in minutes with PromptPay. Trading under a licensed operator also keeps you inside the capital-gains exemption explained on our IOST in Thailand page.

The problem is governance. In July 2026 the SEC filed a criminal complaint alleging that Bitkub hid a theft of about 1.7 billion THB in May 2021 by filing false daily reports. Bitkub says the founders covered the loss and no client lost money. Even if that is true, an exchange that allegedly concealed a hack from its own regulator for years has not earned the right to hold your coins long term.

Bitkub at a glance

Bitkub Online Co., Ltd. is based in Bangkok and was founded in 2018 by Jirayut “Topp” Srupsrisopa. It belongs to Bitkub Capital Group Holdings, and the exchange reportedly earns most of the group’s profit. A planned sale of 51% to SCB Securities was cancelled in 2022, and IPO plans in Thailand and later Hong Kong have been reported, but we found no completed listing.

The IOST/THB market on Bitkub

IOST/THB is one of Bitkub’s oldest markets. Its internal pair ID is 17, and the listing date in Bitkub’s own API is 27 November 2018, a few months before the IOST mainnet even launched. That long history is part of why IOST is a familiar retail coin in Thailand, where people affectionately call it “เหรียญยาย”, the grandma coin. Our guide to what IOST is covers the project itself.

Liquidity is respectable for a local-currency market. When we sampled exchange data, Bitkub’s daily IOST turnover was roughly ten times the IOST/JPY volume at Coincheck or OKJ in Japan, but only around a tenth of Upbit’s KRW market or Binance’s IOST/USDT book. In practice that means small and medium orders fill without trouble, while large market orders will move the price. For the live price in baht, use the ticker in the sidebar or our IOST converter; we don’t print prices in reviews because they go stale within hours.

The weak spot is the spread. On the day we checked, CoinGecko measured the gap between the best buy and sell offers at around 1.4%, far wider than on the big global books. Spreads change constantly, so look at the order book yourself before you trade, and prefer limit orders.

Fees and spread

Bitkub charges a flat 0.25% for both makers and takers on every coin, IOST included. Some reports say the rate falls to 0.10% for very high monthly volume, but we could not confirm that on an official page. For most retail users the 0.25% rate is the one that matters, and it is higher than the large global exchanges charge.

Here is a worked example. Suppose you buy 10,000 THB of IOST and later sell it at an unchanged price. The two trades cost 0.25% each, so about 50 THB in fees. If the spread is around 1.4%, crossing it on the way in and out costs roughly another 140 THB. Your round trip costs about 190 THB, close to 2%, before any withdrawal fee. Placing limit orders inside the spread can cut the second number a lot.

Baht deposits are reported to be free, and baht withdrawals cost around 20 THB to a KBank account with tiered fees for other banks. A single baht withdrawal is capped at 2,000,000 THB. We list these as reported figures because Bitkub’s fee pages block automated checks, so confirm them in the app.

Deposits and withdrawals: memo first

Funding is Bitkub’s strongest point. You can top up with a PromptPay QR code or a transfer from a Thai bank account in your own name, and baht withdrawals go back to that same account. Card purchases are rare on Thai exchanges, and Bitkub is no exception.

Crypto withdrawals are where we hit a wall. We could not confirm which network Bitkub uses for IOST withdrawals or what it charges, because the fee page sits behind a bot check. Bitkub says it updates crypto withdrawal fees four times a day, at 12:00, 16:00, 21:00 and 00:00 Thai time, so any figure we printed would be out of date anyway. Exchanges normally handle IOST on the mainnet, using one deposit account plus a personal memo for each user. Bitkub almost certainly follows that model, but BEP-20 support on BNB Chain is not confirmed.

New accounts face an extra hurdle. Accounts approved from 1 January 2025 had crypto withdrawals suspended from 3 February 2025 until the holder completed additional verification. If you plan to move IOST to a wallet, finish every verification step before you buy.

Not in Thailand? Start with crypto

CEX.IO does not list IOST. Outside Thailand, you can buy crypto or BNB there by card, then send it to an exchange that does list IOST. For Thai residents, Bitkub or Binance TH is the licensed route.

Grab crypto, then IOST

CEX.IO is not licensed by Thailand’s SEC. Trades on SEC-licensed exchanges such as Bitkub may qualify for Thailand’s capital-gains tax exemption; trades elsewhere do not.

The IOST 3.0 airdrop on Bitkub

Bitkub takes part in the exchange share of the IOST 3.0 airdrop. If you held at least 1,000 IOST on Bitkub at the snapshot on 15 March 2025 at 00:00 UTC, you receive a slice every month without claiming anything. The first payout covered four months at once; after that Bitkub moved to monthly rounds, with the 11th paid on 27 May 2026 and the 12th on 30 June 2026. IOST bought after the snapshot does not earn new rounds.

Bitkub has a history here. It also supported the first Donnie Finance (DON) airdrop to IOST holders in February 2021. Our IOST airdrop guide compares Bitkub’s schedule with Coincheck, BitTrade and Upbit, and the IOST 3.0 explainer covers why new tokens are being created at all. Bitkub offers no IOST staking that we could find; for on-chain voting see our staking guide.

License and safety record

Bitkub holds Thai SEC licenses as a digital asset exchange and as a broker under the Emergency Decree on Digital Asset Businesses of 2018, and it appears on the SEC’s current license list among seven licensed exchanges. We could not confirm the license number itself. That license matters for Thai users: since 28 June 2025 Thailand blocks several unlicensed foreign exchanges, and only gains made on licensed venues qualify for the 2025–2029 tax exemption.

The record behind the license is mixed. According to the SEC, as reported in July 2026, Bitkub Online and two former directors filed false daily net-capital reports from 10 May to 30 October 2021. Those reports allegedly hid the theft of about 1.7 billion THB, roughly US$47 million, in 16 digital assets. Bitkub says the co-founders replaced the stolen assets with personal money, that no client lost funds, and that an SEC check of client assets on 8 September 2025 found them intact. The case is a complaint, not a conviction.

1. Nov 2018IOST/THB listedOne of Bitkub’s earliest pairs
2. May 2021Hack of about 1.7bn THBNot disclosed at the time, per the SEC
3. Mar 2025IOST 3.0 airdrop snapshotHolders of 1,000+ IOST qualify
4. Sep 2025SEC check of client assetsBitkub says assets were intact
5. Jul 2026SEC criminal complaintAgainst Bitkub Online and two former directors

It is not the first enforcement action. The SEC previously fined Bitkub over fabricated trading-volume data from 2019, and fined its chief technology officer about 8.5 million THB with a 12-month ban over insider trading. We found no public Merkle proof of reserves and no figure for how much is kept in cold storage.

How to buy IOST on Bitkub

The process takes a few minutes once your account is verified. Thai nationals verify with a Thai ID through NDID or a Dip-Chip check, which can even be done at 7-Eleven. Foreigners living in Thailand need a passport plus a residence document such as a pink ID card, a work permit or a non-immigrant or Smart visa, and can use NFC passport verification. Support is available in Thai and English.

1. Open and verify your account

   Sign up in the Bitkub app and complete identity verification, including any extra step required before crypto withdrawals.

2. Deposit baht

   Scan the PromptPay QR code or transfer from a Thai bank account in your own name.

3. Buy IOST/THB

   Open the IOST/THB market and place a limit order near the best price. The minimum order is 10 THB.

4. Decide where to keep it

   For long-term holding, withdraw to your own wallet after checking the network and memo. See how to send IOST.

Selling is the reverse: sell IOST for baht, then withdraw to your bank. If you want a broader view of buying routes across the region, our how to buy IOST guide covers them.

Pros and cons

Alternatives for IOST in Thailand

Thai options are limited, which is the main reason Bitkub stays relevant despite its record. Gulf Binance, which runs Binance TH, is also SEC-licensed and lists IOST, but only against USDT, so you buy crypto with baht first. Upbit Thailand lists IOST only against bitcoin, and that market is effectively dead. KuCoin Thailand has no IOST at all. Global platforms such as Bybit and OKX are blocked in Thailand, and gains on unlicensed venues lose the tax exemption.

Two licensed routes

For Thai residents the practical choice is Bitkub IOST/THB directly, or baht to crypto on Binance TH and then IOST. Both keep you on SEC-licensed venues.

If you want the deepest IOST market overall, read our Binance review and the full IOST exchanges comparison. Before any purchase, our IOST risk check explains why the token’s price has fallen more than 99% from its January 2018 high and why volatility remains extreme.