# Fund An Organizationally Unique Identifier

> Overview of OUI funding options, DC pricing per uplink, minimum balance requirements, and escrow balance tracking.

[Data Credits](/tokens/data-credit) are used to pay for all transmission of data from devices on the
Helium Network.

It is worth noting that HNT to DC conversion is irreversible. Data Credits cannot be refunded,
exchanged for other tokens, or transferred between wallets.

To fund an OUI with Data Credits, see
[Fund an OUI using HNT](/iot/run-an-lns/fund-an-oui-using-hnt).

## Estimating Usage

<figure className="screensnippet-wrapper">
  <iframe
    src="https://dune.com/embeds/5481819/8933835/"
    frameborder="0"
    width="100%"
    height="425px"
    style={{ borderRadius: 16, paddingBottom: `0.5rem` }}
  ></iframe>
  <figcaption>
    Up-to-date usage metrics for all IoT OUIs on the Helium Network.  To get a sense of
    traffic and DC usage on the network, check out the full{' '}
    Dune Data Credit Dashboard.
  </figcaption>
</figure>

Data Credits are charged at 1 DC per 24-byte increment for each purchased copy of an uplink payload.
DC cost is based on the application payload size only. LoRaWAN protocol overhead (headers, MIC,
etc.) does not count toward the DC cost. For a helpful visualization of DC usage of devices for a
given period, check out the [Data Credit calculator](/tokens/data-credit#data-transfer-calculator)
in the DC documentation.

Only uplinks are charged on Helium. Downlinks and join requests are not billed.

## Tracking OUI Balance

The balance of an OUI is held in an escrow account that is generated based on the OUI's payer key.
This escrow account is what allows the Helium Network to appropriately deduct DC as network transfer
occurs. The widget below can be used to look up the escrow account and balance for payer or router
keys associated with any valid OUI.

  <EscrowOUIWidget />

The escrow account is the main source for understanding the remaining balance of an OUI. Details on
the funding and burn of Data Credits on an escrow account can be inspected using any Solana
blockchain explorer.

When monitoring the OUI balance, it is worth noting that the minimum usage deducted at a time is
10,000 DC[^1].

[^1]:
    `BURN_THRESHOLD` on
    [GitHub](https://github.com/helium/oracles/blob/7c9f5b4e6f8e47be80eaf3c6cb4cc703373246ef/iot_packet_verifier/src/pending_burns.rs#L32)

## Minimum Balance

The Helium Packet Router enforces a minimum balance of 3,500,000 Data Credits (\$35). This minimum
balance is required to ensure that all Hotspots are compensated for their work on the network in the
case that the LNS transfers data more quickly than can be deducted from the OUI's balance. Token
balances cannot become negative, so this \$35 buffer keeps network payments balanced.

If the DC balance of an OUI falls below the minimum balance, the OUI will be unable to receive data
until the balance is increased. The Packet Verifier checks the DC balance of every locked OUI every
30 minutes and unlocks it if its DC balance is above 3.5MM DC.