quote_mismatch — top-up quote is stale

The confirmed top-up did not go through: the order was not created and nothing was charged. Body: reason: "quote_mismatch", actual_lmc_minor (what it costs now), quoted_lmc_minor (what it was in the quote).

Between the issuance of the quote_token and your confirmation, a parallel order consumed part of the quota, and the top-up got more expensive. The server deliberately does not charge more than it showed the user — so it refuses instead of silently recalculating.

The difference actual_lmc_minor − quoted_lmc_minor is the price increase; it is in minor units, and what you should show the user is shortfall_lmc from the next quote. The old quote_token is no longer valid: submitting it again guarantees the same 409.

Repeat POST /orders WITHOUT confirm_payg_topup and without quote_token → a new 402 with a fresh price; show it and confirm again. The same sequence applies to POST /orders/{order}/retry — it goes through the same billing flow.

• payg_topup_required — where the cycle starts
• Guide: LMC, quotas, and PAYG
• POST /orders
• POST /orders/{order}/retry
• Wallet