The cheapest top-up method depends on two things: the on-chain transfer fee and the card issuer’s deposit markup for that chain. Most readers focus only on the first — but the second is often the larger cost.
On-Chain Transfer Fees: TRC20 Is Usually Far Cheaper Than ERC20
There are two mainstream chains for USDT transfers:
- TRC20 (Tron): Requires TRX to cover energy and bandwidth. The equivalent cost is typically under $1. When withdrawing from an exchange, the platform bundles this into a flat withdrawal fee (which varies by platform), while the underlying on-chain cost itself is very low.
- ERC20 (Ethereum): Consumes ETH directly as gas. Fees fluctuate with network congestion — you can check real-time costs on Etherscan Gas Tracker. Even during quiet periods, ERC20 gas tends to exceed TRC20.
The conclusion is straightforward: looking at network fees alone, TRC20 almost always wins. But that is only half the picture.
Issuer Markups: The Hidden Cost Most People Miss
Many card issuers charge different “deposit markups” or “channel fees” depending on which chain you use. The reason: TRC20 is widely used among Asia-Pacific users, so some issuers charge a premium for it. Meanwhile, ERC20 may carry a lower markup because certain setups integrate directly via wallet, reducing issuer overhead.
Here is a hypothetical scenario (always verify actual numbers on the issuer’s official fee page):
- Assume the issuer charges a 1.5% markup on TRC20 and 0.5% on ERC20
- You top up 1,000 USDT
- TRC20 credited amount: approx. 985 USDT + under $1 in network fees
- ERC20 credited amount: approx. 995 USDT + gas depending on network conditions
As long as ERC20 gas is not unusually high at that moment, ERC20 comes out cheaper overall.
This is why we consistently stress: do not assume TRC20 is always the cheaper option.
How to Pick the Cheapest Option
Follow these three steps before topping up:
- Open the issuer’s official fee page and locate the “top-up” or “deposit” section. Note the markup percentage for both TRC20 and ERC20.
- Check current on-chain gas. ERC20 gas can occasionally spike above $10 during peak periods — at those times, TRC20 almost certainly wins.
- Calculate the total cost: exchange withdrawal fee + on-chain gas + issuer deposit markup. Go with whichever chain is lower.
If you frequently top up small amounts (e.g., a few tens of dollars for ChatGPT Plus), network fees represent a larger share of your total, so TRC20 is usually preferable. If you are funding thousands of dollars in a single transaction — where fees are negligible relative to the amount — focus primarily on which chain carries the lower markup.
Editorial Note
Do not let the “TRC20 = cheap” consensus in crypto circles make the decision for you. Spending 30 seconds checking the issuer’s deposit markup page before each top-up can save you meaningfully over time. If you are based in the Asia-Pacific region, see our editorial pick MPCard Asia Elite review, or compare Bybit Card and RedotPay deposit channels side by side.
For specific cost-saving approaches on small subscription payments like ChatGPT or Claude Code, see ChatGPT Plus subscription and Claude Code. Readers looking to minimize overall usage costs can also browse lowest-fee card recommendations.