## Documentation Index

Access the complete documentation index at:
https://www.zoho.com/en-fr/books/kb/llms.txt

Use this file to discover all available documentation pages before proceeding.

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# How Are Old Invoice Numbers Handled During Import?

When invoices are imported, the current numbering series in Zoho Books is applied to those invoices. The old transaction number can be added in a [custom field](https://www.zoho.com/en-fr/books/help/settings/customization/custom-fields.html#create-custom-field) for reference.