## Zoho Inventory Documentation Index

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

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

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# I’m unable to create a transaction for a contact. Why?

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This might happen due to the contact type being wrongly specified. A contact can either be indicated as a vendor (sells goods or services to you), customer (buys goods or services from you) under the field **Contact Type**.

*   Contacts marked as **Customer** can only be involved with sales orders, invoices and invoice payments. Bills and purchase orders cannot be created for them.
*   Contacts marked as **Vendor** can only be involved with purchase orders, bills and bill payments. Other transactions cannot be started for these contacts.

A contact can be changed anytime from a vendor to a customer and vice-versa, by editing the **Contact Type** field in the **Contact Details** page.

**Note:** Contacts associated with transactions cannot be changed from one type to another. To do so, you have to delete those transactions and try again.