# Transaction speed

![Transaction speed](/files/-MRaTc8541mGGpChnkhC)

What does transaction speed mean?

First of all, transaction speed applies only to on-chain invoices. All lightning invoices are instantly marked as complete.

To understand why transaction speed setting is needed, you need to understand the invoice statuses in Bitcart:

When invoice has just been created, it has `pending` status.

If no payment has been sent within the invoice time frame (expiration time), invoice is marked `expired`. Expired invoices no longer listen for incoming payments, but you may manually mark it complete.

If a payment has been sent within the invoice time frame (expiration time), invoice status is set to `paid`.

With `paid` status, customer is redirected to the redirect URL, and checkout page shows paid. But all the notifications, emails and custom scripts aren't executed yet.

When payment has been confirmed (has >= 1 confirmations), invoice status is set to `confirmed`.

When payment's number of confirmations is >= transaction speed, invoice status is set to `complete`, and all the postorder actions are executed (like notifications).

So, transaction speed controls how fast you want your invoice to be complete. Default value of 0 provides the fastest checkout, but it is not always good for your use case, it might be not safe.

Value of 1 means waiting for one confirmation, which is enough in most cases.

You can set transaction speed to any value between 0 and 6 (there is no point in waiting past 6 confirmations).


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.bitcart.ai/guides/transaction-speed.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.