Your balance on Canton is held as many separate pieces rather than one number. When too many build up, transactions get expensive and eventually stop working. Merging fixes it. This page explains why, and what to do if the wallet is asking you to merge right now.

If you were using Loop before automatic merging was introduced, you almost certainly have pieces that built up beforehand. Automatic merging does not clear those, you need to merge them once yourself.

Your balance is safe throughout. Merging does not change how much you hold, and a transaction that is rejected costs you nothing.

On Canton, your balance is not stored as a single number. Every transfer you receive is recorded on the network as its own separate piece. Each of those pieces is called a UTXO. Receive ten transfers and you hold ten pieces, even though your wallet adds them up and shows you one total.

Ten transfers received means ten separate pieces, shown to you as one total.

Imagine paying for everything in cash. Every time someone hands you money, you drop it in your pocket without organising it. Over months your pocket fills with coins.

Now you want to pay for something. You have the amount, but you have to count out a handful of coins to do it. It takes longer, it is heavier to carry, and if you were charged by weight you would be paying more than someone holding a single note.

That is what is happening in your wallet. The balance is the same either way, but a transaction that has to reach into many pieces is physically larger, and the network charges by size. A wallet holding many pieces can pay close to double what a consolidated wallet pays for exactly the same action.

Merging combines your pieces into fewer, larger ones. Your balance does not change by a single unit. What changes is the size, the speed and the cost of everything you do afterwards.

Two things. Your pieces have built up over time, which makes each transaction bigger. And since the Fee Balance was introduced, the network fee is shown to you directly rather than handled out of sight. The amount you pay is the network's own cost. Loop does not set it and adds nothing on top of it.

Because the cost is not a fixed tariff. It is calculated from the shape of the transaction: how much data it carries, who the recipient is and how they are hosted, the number of signatures required, and how many pieces are being spent. It is not priced by how busy the network is.

No. Merging does not change your balance, it only reorganises how it is held. If a transaction is rejected, nothing is charged and nothing moves. Your holdings stay where they are throughout.

Once an asset passes a certain number of pieces, it can no longer be handled in a single transaction, and the wallet asks you to merge before you go on. The screen tells you which asset and how many pieces you hold.

The merge prompt names the asset and how many pieces you are holding of it.

Yes. Every asset accumulates its own pieces and is counted on its own. Merging your CC does not affect your USDCx, and the wallet will ask about each one that has built up.

Usually for the same reason. If you hold too many pieces, the transaction cannot be prepared at all, so there is no fee to display and the Confirm button stays disabled. Merge first, then try again.

The same problem, stated by the network. The transaction tried to spend more pieces than it is allowed to reference at once and was rejected before it started. Nothing was charged and nothing was lost.

UTXO Management lets the wallet merge your pieces in the background once an asset builds up past a certain point, so you never have to think about it.

In Settings, under UTXO Management. It asks for a one-time approval the first time, and the wallet will prompt you for it.

The UTXO Management setting, further down in Settings.

It is optional, but if you never gave that approval, no automatic merging has been running on your wallet and your pieces have been accumulating the whole time. This is the most common reason people find themselves with a large backlog.

No. Automatic merging keeps things tidy from the point it is switched on. It does not clear pieces that had already built up before then. That backlog has to be cleared once, by you.

A merge is a transaction on the network, so it carries a network fee like any other, taken from your Fee Balance. It is charged in CC at cost, with nothing added on top, and it is capped.

For a merge you start yourself, the wallet shows you the estimated amount before you confirm. For automatic merging, it shows you the current values before you turn the setting on. Treat any figure as a guide rather than a fixed price, because the charge is calculated at the moment the merge runs.

In your History. Open the transaction and the fee is shown in the detail, along with the transaction hash.

Give it a moment and check again. If the pieces have come down and the cost has not, send us your party ID and the transaction and we will read the record for you.

Topping up is itself a transaction, so it needs a small amount of Fee Balance to go through. If yours has dropped below that point you cannot fix it from inside the wallet, and retrying will not change anything.

Write to [email protected] with your party ID. We credit your Fee Balance by hand, at no charge, and you carry on from there. How to top up your Fee Balance has the detail.

Switch on automatic merging and leave it on. Once it is running the wallet keeps your pieces consolidated on its own, and you should not see the merge screen again.

If you integrate with the server SDK, the handling is different on your side. See docs.fivenorth.io/loop-sdk/overview for how to manage Fee Balance and transaction preparation programmatically, and Integration rules and troubleshooting for the rules around retries.

Message us from this page, or write to [email protected], with your party ID, what you were trying to do, and a screenshot if you have one. We can read the public record and tell you exactly what happened.