SPL tokens are the tokens created through Solana's shared Token Program, the standard behind almost every asset on the network. Token-2022, also called Token Extensions, is the newer version of that program, and it adds opt-in features such as transfer fees, confidential transfers, and permanent delegates. Every Solana token except SOL itself follows one of these two standards.
The mechanic behind both standards is unusual: Solana does not give each token its own smart contract, the way Ethereum does. On Solana's network, one shared program keeps the books for thousands of tokens at once, and Token-2022 is simply a second edition of that program with optional extra pages. The same pair shows up in real life: the USDC in your wallet is a classic SPL token, while PayPal's PYUSD stablecoin runs on Token-2022.
Some of those optional pages give an issuer standing power over the tokens in your wallet, which is why reading a token's standard is a safety skill and not trivia.
How one program runs thousands of tokens
Solana has no separate contract per token. One shared program, the SPL Token Program, manages every token that uses it. Creating a new token means adding a new "mint" record inside that program, and holding a token means having a small token account that the same program keeps updated for you.
Think of one spreadsheet application serving thousands of companies. Nobody rebuilds Excel for a new budget; they open a new sheet inside software everyone trusts. The mint is that sheet's header row: it records the token's total supply, its decimal places, and who, if anyone, can create more. Your balance lives in a token account, a tiny on-chain record that says "this wallet holds this much of this mint" (source: Solana token documentation).
Two practical details follow. First, each token account holds a small refundable deposit, about 0.002 SOL, or roughly $0.30 if SOL trades at $150, to pay for its storage space. Close the account and the deposit comes back. Second, those deposits and every fee on the network are paid in SOL, the native coin, which is not an SPL token itself. The token programs run on top of Solana's account architecture like any other application.
That one-program design ran the network's entire token economy for years. Then issuers started asking for things it could not do.
Why Solana built a second token standard
Token-2022 exists because the original Token Program was deliberately minimal. Stablecoin issuers wanted compliance controls, projects wanted built-in fees, and institutions wanted privacy. None of that could be added safely to a program thousands of live tokens depended on, so Solana's engineers shipped a second program, and both now run side by side.
Changing the original program in place was never a real option, because wallets, exchanges, and DeFi apps all assume it does precisely what it has always done. The safer path was to publish a new program with its own address and let issuers opt in. It works like revising a paper form: the new version is used for new filings, while every form already in the cabinet stays valid as filed.
For a holder, the key facts are reassuring. Token-2022 keeps every classic operation, and it has passed multiple third-party security audits (source: Token-2022 program documentation). A Token-2022 mint with no extensions enabled behaves just like a classic SPL token. Both standards settle on the same network, pay the same base fee, and get ordered by the same Proof of History clock. Token-2022 is the current-generation choice for new launches, but classic SPL is not deprecated, and giants like USDC still use it.
So what do the optional extras actually do? The extensions are the whole story, and a handful matter far more to holders than the rest.
The Token-2022 extensions that matter to holders
Token-2022 offers roughly a dozen optional extensions. For a holder, six deserve attention: transfer fees, interest-bearing display, non-transferable tokens, permanent delegates, transfer hooks, and confidential transfers. Each one changes what can happen to tokens sitting in your wallet, and the differences between them are bigger than the shared label suggests.
Here is the holder's-eye view:
| Extension | What it does | Who uses it legitimately | What it means for you |
|---|---|---|---|
| Transfer fee | Skims a set percentage from every transfer | Reward-sharing or revenue tokens | Every hop costs you the fee; check the rate before buying |
| Interest-bearing | Displays a balance that grows at a set rate | Bond-like or time-based instruments | Display math only; nobody deposits real yield into your wallet |
| Non-transferable | Locks tokens to one wallet ("soulbound") | Credentials, badges, achievements | You cannot sell or move it, by design |
| Permanent delegate | Lets a named authority move or burn tokens from any account | Regulated stablecoins meeting legal orders | The issuer can reach into your wallet; trust decides everything |
| Transfer hook | Runs extra program logic on every transfer | Compliance checks, royalty enforcement | A transfer can be blocked or modified by code you did not call |
| Confidential transfer | Encrypts amounts and balances | Payroll, institutional payments | Privacy for the numbers, covered in the next section |
| Default account state | New holder accounts start frozen until approved | Permissioned or RWA tokens | You may need issuer approval before the token even moves |
There are also housekeeping extras, like storing a token's name and logo on the mint itself. The first prominent transfer-fee token shows how the mechanics feel in practice. BERN, a token in the Bonk ecosystem, launched with a 6.9% transfer fee split between holder rewards, buybacks, burns, and a developer fund (source: Helius research on Token-2022). The program collected the fee automatically on every transfer, so holders never had to trust a promise.
Pin one warning to the interest-bearing row. The extension changes how a balance is displayed, not how value arrives, so a token showing 5% "interest" is doing cosmetic math unless the issuer backs it separately. Real Solana yield comes from staking SOL with validators, and the liquid staking tokens that represent staked SOL, compared in our guide to native and liquid staking, are themselves ordinary SPL tokens.
One extension from the table deserves its own section, because it is the most ambitious and the most misunderstood.
Confidential transfers: private amounts, public accounts
Confidential transfers encrypt the amount of a transfer and the balances of the accounts involved, while the sender, the receiver, and the fact that a transfer happened stay public. It is privacy for the numbers, not anonymity for the people, and issuers can keep an auditor key that decrypts amounts when the law requires it.
Picture a sealed envelope. Anyone watching the mail can see who sent it, who received it, and when it moved, but the dollar figure written inside is hidden. A business can pay salaries on-chain without publishing every employee's pay, yet a regulator with the right key can still audit the flow (source: Solana confidential transfer documentation).
This is also where PYUSD makes the whole standard concrete. PayPal's stablecoin, issued by Paxos, chose Token-2022 for its compliance toolkit. A permanent delegate lets the regulated issuer freeze or seize funds under legal order, and confidential transfer support adds payment privacy (source: PayPal's PYUSD token-extensions deep dive).
The honest status report has a bump in it. The zero-knowledge proof program these transfers depend on went live on Solana's mainnet in spring 2025, and within weeks a researcher privately reported a flaw: a crafted fake proof could have passed verification. Core engineers patched validators and switched the proof machinery off pending a full audit (source: Solana's June 2025 post-mortem). No funds were lost, and the feature has stayed off by default while that audit runs, so real-world confidential-transfer usage remains very early. The episode reads less like a scandal than like the system working: a caution flag, not a green light.
Privacy is the opt-in, audited end of the extension list. Other extensions tilt power toward the issuer, and that is where a buyer should slow down.
Which extensions are risk flags before you buy
Three extensions deserve a hard look on any unfamiliar token: a permanent delegate, a high transfer fee, and a default-frozen account state. None of them is a scam by itself. Each one, though, gives the issuer standing power over tokens in your wallet, so the real question is always who the issuer is.
Take the permanent delegate first; it is the bluntest. Security researchers describe it plainly: the delegate can transfer or burn any amount from any token account of that mint, forever (source: Neodyme security research on Token-2022). When the delegate is a regulated trust company answering to a state financial regulator, as with PYUSD, that power is a legal requirement with accountability attached. When the delegate is an anonymous memecoin team, the same switch means your balance can vanish because someone decided it should. Identical code, opposite risk.
Transfer fees earn a spot on the list because of arithmetic, not because fees are dishonest. Suppose you put $500 into a token carrying an 8% transfer fee. The buy itself costs you $40, leaving $460 of exposure, and selling later skims roughly another $37 on the way out. Two hops have cost you about 15% before the price moved at all. Worse, scam launches have set fees near 100%, which turns the token into a honeypot: you can buy in, but nearly all value is skimmed away when you try to sell. Checking the fee rate takes seconds and can save the whole position.
Default-frozen accounts and transfer hooks round out the flags. A token whose new accounts start frozen until the issuer approves them is normal for a permissioned real-world-asset product. For anything sold as a free-trading community token, it is alarming. A transfer hook, extra code that runs on every transfer, is fine when audited and public, but it can also block sells outright. From Blofin's operational perspective, the extension list is one of the first things an asset review reads. A token's mint shows which program owns it, and a permanent delegate or transfer fee changes how deposits and withdrawals must be handled before that asset can go live. Trading tools help too: the aggregator covered in our guide to swapping on Jupiter surfaces fee and freeze flags before you confirm.
None of this requires developer tools. The labels are public, and reading them takes about a minute once you know where to look.
Living with both standards day to day
In everyday use you rarely choose a standard, because the token you want already has one. Modern wallets support both programs, sending and receiving works identically, and the one new habit worth building is a short explorer check before you buy any token you have never held.
The check works like this:
- Copy the token's mint address from a source you trust, such as the project's official site, never a chat message.
- Paste it into a Solana explorer like Solscan or the official Solana Explorer.
- Read the program field. It will say either the classic Token Program or Token-2022 (Token Extensions).
- If it says Token-2022, open the extensions list and scan for the flags from the previous section: permanent delegate, transfer fee percentage, default account state, transfer hook.
- Check who holds the authorities. A fee rate controlled by a public, accountable issuer is a different fact from the same rate controlled by an anonymous wallet.
Everything else about holding tokens stays familiar. A wallet like Phantom, covered in our Phantom wallet setup guide, shows classic and Token-2022 assets side by side. It creates token accounts as you need them, each with the small refundable deposit covered earlier.
The mechanics of sending and receiving on Solana are the same for both standards. And every fee and deposit is paid in the native coin, so you will always want a little SOL on hand, which starts with knowing how to buy SOL on an exchange.
That is the whole standard: one shared program, a second edition with optional powers, and a one-minute label check that tells you which powers apply.
Frequently asked questions
Is SOL itself an SPL token?
No. SOL is Solana's native coin, built into the protocol rather than issued through a token program. It pays fees and gets staked to secure the network. When DeFi apps need SOL to behave like a token, they use wrapped SOL, an SPL-token version you can convert freely. Unwrapping it returns native SOL to your wallet.
Are SPL tokens the same as ERC-20 tokens?
They solve the same problem on different machinery. ERC-20 is Ethereum's standard, where each token is its own deployed contract, while SPL tokens are entries managed by Solana's shared token programs. A token that exists on both chains, like USDC, is really two separate issuances that the issuer keeps interchangeable. Bridged versions are IOU-style claims created by a bridge, and they carry that bridge's risk.
Will old SPL tokens be migrated to Token-2022?
No. A token's mint is created under one program and stays there permanently, because the two programs have different addresses and cannot exchange mints. There is no forced upgrade and no sunset date for the classic standard. If a project wants Token-2022 features, it must launch a new mint and persuade holders to swap, which is rare and always announced through official channels.
Do Token-2022 tokens cost more to send?
Not at the network level. The base fee for a Solana transaction is the same tiny amount, currently 0.000005 SOL per signature, whichever token program is involved. The only extra cost appears when a token carries the transfer-fee extension, and that fee goes to the issuer's chosen recipient, not to the network. A token with no transfer fee costs the same fraction of a cent to move as a classic SPL token.
Can an issuer add extensions to a token after launch?
Mostly no. Extensions are set when the mint is created, which is why the explorer check is so useful: the list you see is the list that exists. The nuance is that some extensions have adjustable parameters, so a transfer-fee rate can be changed later by whoever holds the fee authority. That makes the authority holder part of your risk read, not just the current rate.
Why do some Solana apps still not support Token-2022 tokens?
Because every extension adds accounting edge cases that an app must handle correctly or refuse. A DeFi pool that ignores transfer fees, for example, would slowly misprice itself, and a lending market must decide what a permanent delegate means for collateral. Major wallets and aggregators now handle Token-2022 well, but a long tail of apps still accepts only classic SPL tokens.
Researched and written by the Blofin Academy editorial team with AI-assisted drafting. Primary sources include the Solana token documentation, the Token-2022 program documentation, the Solana confidential transfer documentation, Solana's June 2025 post-mortem, PayPal's PYUSD token-extensions deep dive, Helius research on Token-2022, and Neodyme security research on Token-2022. All facts independently verified against cited documentation current as of July 2026.
This article is for informational purposes only and does not constitute financial advice, investment guidance, or a recommendation to buy, sell, or hold any digital asset. Cryptocurrency markets involve significant risk and you should conduct your own research and consult qualified professionals before making investment decisions. Blofin Academy content reflects the state of public information at time of publication; protocol parameters, fees, and ecosystem data change frequently.