> ## Documentation Index
> Fetch the complete documentation index at: https://www.aiaccountant.com/help/llms.txt
> Use this file to discover all available pages before exploring further.

# Start a reconciliation

> Open the setup panel, choose the GSTIN, and pick the return period you want to reconcile.

## Open the setup

1. On the GST module landing page, click **Get Started**.
2. On the GSTR-2B screen, click **Start Reconciliation**.

A setup panel slides in from the right, titled GSTR-2B Reconciliation, with your organisation name at the top.

## Choose the GSTIN

Select the GST registration you are reconciling for.

If it is not listed, click **Add New GSTIN** and add it. You can add several GSTINs under the same PAN. This is a one-time setup, so once a GSTIN is in, it stays.

## Choose the return period

Pick the period you want to reconcile. This can be:

* a single month, or
* a full range, such as April to March for the whole financial year.

Running the entire year at once is the easiest way to catch credits you may have missed in earlier months, because an invoice that appeared in your 2B in a later month than your books still gets matched.

## Next

Fill in the two data sections in the same panel:

<CardGroup cols={2}>
  <Card title="Bring in GSTR-2B" icon="cloud-arrow-down" href="/help/gst/fetch-or-upload-gstr-2b">
    Fetch from the portal, or upload a file.
  </Card>

  <Card title="Purchase register" icon="file-import" href="/help/gst/upload-and-map-purchase-register">
    Upload your books and map the columns.
  </Card>
</CardGroup>