Collect Tax
Once you own parcels on merca.earth, you can collect tax balances and manage your portfolio. For expand, rebalance, acquire, and merge operations, see Territory Operations.
Your Land Portfolio
All your parcels appear in the Polygon List sidebar under "Registered Geometry." Each card shows:
- Parcel ID — truncated on-chain identifier, linked to the block explorer.
- Area — total area in square meters or square kilometers.
- Parts and vertices — convex parts count and total vertices. Complex shapes need more parts.
- Price per square kilometer — base price times the parcel's premium multiplier.
- Buyout price — what another user would pay to force-purchase.
Click any parcel in the list or on the map to open the Selected Parcel Panel with options to expand, collect taxes, edit the visual layer, or remove.
The "Mine" badge marks your parcels. Others show the owner's address and a "Buy Parcel" button.
Tax Obligations
merca.earth uses a Harberger-inspired tax model (see Buyout & Premium → Every Parcel Is Always for Sale). When someone registers or buys a parcel, a portion of the payment enters a hierarchy pool. The split depends on the operation:
Registration (first-time claim)
| Destination | Share |
|---|---|
| Protocol treasury | 92% |
| Hierarchy pool | 8% |
Buyout (purchasing from an existing owner)
| Destination | Share |
|---|---|
| Seller | 85% |
| Protocol treasury | 7% |
| Hierarchy pool | 8% |
How Tax Buckets Work
Pool funds flow into tax buckets — time-bucketed escrow records on the parcel's on-chain record. These accrue over configurable epoch windows and become claimable by owners of parent-level parcels that geographically contain the taxed parcel.
What Happens if You Do Not Collect
Tax buckets have an expiry window. If the parent-level owner does not collect before expiry, anyone can call sweep_expired to return uncollected funds to the treasury. Expired buckets carry no penalty for the child parcel owner — the obligation falls on the parent.
Uncollected tax buckets are permanently lost once they expire. Anyone can call sweep_expired to send the funds to the protocol treasury — there is no way to recover them after that.
Claiming Tax Revenue
If you own a parent-level parcel that geographically contains child-level parcels, you can collect tax flow whenever those children are involved in transactions feeding the hierarchy pool.
How to collect
- Select your parent-level parcel.
- The Selected Parcel Panel shows a Taxes section. If collectable buckets exist, the total appears with a "Collect" button.
- Click Collect. This executes
collect_taxper child parcel, processing up to 20 children per transaction. Collection and withdrawal happen atomically in the same call — SUI transfers to the parcel owner immediately, with no separate withdrawal step.
collect_tax is permissionless — any sender can trigger it, but the tax always goes to the parcel owner. Each call emits a TaxCollected event per child with the amount collected, the share kept by the collector, and the amount forwarded upstream. A TaxWithdrawn event is emitted in the same transaction when funds transfer to the owner.
Monitoring tax flow
The parcel detail view shows:
- Child parcel count contained by your parcel.
- Opened tax buckets targeting your level.
- Collectable bucket count and total amount.
- Expired (sweepable) buckets you missed.
Watch expiry windows. Uncollected buckets become sweepable by anyone, returning funds to the treasury.
Removing a Parcel
Click the trash icon on the sidebar card. The on-chain remove function:
- Cleans up the parcel's PriceState record.
- Sweeps remaining tax buckets.
- Removes the parcel from the spatial index.
Removal is irreversible. The land becomes unclaimed and available for anyone to register.
Removal cannot be undone. Once removed, your parcel becomes unclaimed land that anyone can register — potentially at a different price. Make sure you have collected all outstanding tax before removing.
See also: Territory Operations · Tax → What a Tax Bucket Is · Cash Flows → Tax Collection · Pricing → Registration Price · Buyout & Premium → Every Parcel Is Always for Sale