# Fees

Every fee StampDEX charges, who pays it, how the network fee is estimated, and a worked example including the case where the minimum dominates.

> Source: bitcoinuniverseio/stampdex (private application source), src20 marketplace service fee constants, src20 PSBT service, mempool fee normalisation. Applicable release continuous deployment, verify with GET /api/version. Last verified 2026-09-01. Chain bitcoin/mainnet.

import FeeExplorer from '../../../components/explainers/FeeExplorer.astro';


Every fee is stated before you sign. There are no hidden fees. There is one fee that
surprises people, and it is in the second table.

## SRC-20 marketplace trades

<FeeExplorer />

| Fee | Amount | Who pays |
| --- | --- | --- |
| Service fee | 1.5% of the trade total, with a 500 sat minimum, **per side** | The buyer pays one, the seller pays one |
| Network fee | Set by the fee rate you choose, in sat/vB | Whoever signs the transaction that pays it |

Both sides pay, so **a trade carries 3% in total**. The seller's side is deducted from
their payment; the buyer's side is funded by the extra sats the buyer sends. The two
fees are paid together as a single output in the settlement transaction.

### The minimum dominates on small trades

The 500 sat floor is per side, and the smallest trade StampDEX will list is 2,000 sats.

| Trade total | Buyer fee | Seller fee | Total fee | As a share of the trade |
| --- | --- | --- | --- | --- |
| 2,000 sats | 500 | 500 | 1,000 | 50% |
| 20,000 sats | 500 | 500 | 1,000 | 5% |
| 33,334 sats | 500 | 500 | 1,000 | 3% |
| 100,000 sats | 1,500 | 1,500 | 3,000 | 3% |
| 460,000 sats | 6,900 | 6,900 | 13,800 | 3% |

Above roughly 33,334 sats the percentage takes over and the all-in cost settles at 3%.
Below it, the floor is what you are paying. This is arithmetic, not a penalty, but it is
worth knowing before you list something small.

## SRC-20 mint, deploy, and transfer

Every SRC-20 transaction StampDEX builds outside the marketplace, a mint, a deploy, or
a plain transfer, carries a flat **1,500 sat platform fee**, the same fee the Universe
Inscribe app charges. It appears as its own output in the transaction your wallet
shows.

## Bitcoin Stamps

**No StampDEX fee.** A stamp purchase pays the dispenser's asking rate and the Bitcoin
network fee. Opening and closing a dispenser pays only the network fee.

## Where the service fee goes

To a single fixed pay-to-Taproot output:

```
bc1pl0xdhr5delrk80d6s5h5qa9awsf7qzc45jl8na6ns8vp3e0vv7wqxattxy
```

It is a constant, not a per-user address, and it is visible on chain in every SRC-20
settlement and in every deploy, mint, or transfer StampDEX builds. Check it in the
transaction your wallet shows you. See
[Review a PSBT before signing](/docs-stampdex/guides/psbt-review/).

## Network fees

Bitcoin transactions pay miners by size, not by value.

```bash
curl https://stamp.api.bitcoinuniverse.io/api/v1/market/fees
```

You get five tiers: fastest, half hour, hour, economy, and minimum. If any tier is
missing or is not a number, the whole response is rejected with an error rather than
served partially.

- The estimate is cached for about 60 seconds.
- If you do not choose a rate, the half hour tier is used, falling back to 25 sat/vB
  when no estimate is available.
- Your chosen rate is applied when you buy, so a seller's listing-time rate is not
  imposed on you.
- Nobody can guarantee a confirmation time. The rate buys a position in a queue, not a
  promise.

## Dust outputs are not fees

An SRC-20 transaction carries several tiny outputs that are protocol structure, not
charges:

| Output | Value | Goes to |
| --- | --- | --- |
| Recipient marker | 330 sats | The buyer, as the output the transfer credits |
| Data chunk | 330 sats each | The encoded transfer itself |
| Seller anchor | 548 sats | The seller, returned |

None of them go to StampDEX.

## Browsing is free

Exploring markets, stamps, collections, and the public API costs nothing and needs no
wallet.

## Related

- [Buy SRC-20](/docs-stampdex/guides/buy-src20/)
- [Sell SRC-20](/docs-stampdex/guides/sell-src20/)
- [Review a PSBT before signing](/docs-stampdex/guides/psbt-review/)