> ## Documentation Index
> Fetch the complete documentation index at: https://whalescorp.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# USDC Accounting Specifics

## Invoice Denomination

Invoices denominated in **USDC** (\~\$1.00 USD, Circle-managed peg).

Recommended columns (partially implemented):

```text theme={null}
subtotal_usdc   NUMERIC(18,6)   -- primary
subtotal_usd    NUMERIC(18,6)   -- USD equivalent (planned)
rate_at_invoice NUMERIC(12,6)   -- USD/USDC at issuance (planned)
rate_source     TEXT            -- 'circle_api' | 'assumed_peg' (planned)
```

## Settlement Documents in Non-USD Currencies

Settlement statements (§2.5) involve FX conversion when the merchant operates in a non-USD currency. Store:

```text theme={null}
face_value_usdc     NUMERIC(18,6)   -- always in USDC
settlement_currency TEXT            -- e.g. 'EUR'
fx_rate             NUMERIC(12,6)   -- USDC → settlement_currency at settlement date
fx_rate_source      TEXT            -- 'ecb', 'coinbase', 'manual'
amount_due          NUMERIC(18,6)   -- face_value_usdc × fx_rate, in settlement_currency
```

This is the authoritative amount the merchant owes. The FX rate is fixed at the time the settlement statement is **issued**, not at payment time — protecting both parties from rate drift during the payment window.

## Revenue Recognition

Under IRS guidance (Notice 2014-21, Rev. Rul. 2023-14):

* USDC received = ordinary income at FMV at receipt time
* FMV for USDC ≈ \$1.0000 (trivial, but must be documented)
* Store `usdc_rate_at_collection` and `usd_fmv` on every `fee_ledger` collected entry (planned)\\

## On-Chain Payment Proof

`fee_ledger.collection_tx_hash` and `merchant_settlements.payment_ref` (Solana tx sig for crypto payments) are the immutable receipts. Verifiable at [solscan.io](http://solscan.io).

## Invoice Payment Instructions

```text theme={null}
Payment Network: Solana (Mainnet)
Payment Token: USDC (SPL)
Payment Address: [platform USDC wallet]
Memo: [invoice_number or settlement_number]
Amount: [total_usdc] USDC
Rate Source: Circle USD/USDC (at invoice date)
```


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