---
title: "Error E2121 – Manual Numbering Not Allowed"
description: "Error E2121 – Manual Numbering Not Allowed"
keywords: "Error E2121 Manual Numbering Not Allowed NAV BC error message"
url: "https://myrapidi.com/wiki/error_e2121_manual_numbering_not_allowed"
locale: "en"
published: "2025-07-17T10:41:16Z"
modified: "2025-07-17T10:41:17Z"
---

When you receive the following error message :  
  
_E2121 - ECE\_SOAPFaultResponse: We received an error response from the server: FaultCode: Client String.....: You may not enter numbers manually. If you want to enter numbers manually, please activate Manual Nos. in No. Series AA-INV. detail: [string: You may not enter numbers manually. If you want to enter numbers manually, please activate Manual Nos. in No. Series AA-INV. Attributes: xmlns = "http://schemas.microsoft.com/2003/10/Serialization/"] , Data sent: \<soap:Body\>\<CreateMultiple xmlns="urn:microsoft-dynamics-schemas/page/salesinvoice"\>\<SalesInvoice\_List\>\<SalesInvoice\>\<No\>LV00001\</No\>\<Sell\_to\_Customer\_No\>1234\</Sell\_to\_Customer\_No\>\<Your\_Reference\>0Q0Q5000002knsbKAA\</Your\_Reference\>\<External\_Document\_No/\>\<Stripe\_ID/\>\<SalesLines\>\<Sales\_Invoice\_Line\>\<Type\>G\_L\_Account\</Type\>\<No\>1041\</No\>\<Quantity\>1.000000\</Quantity\>\<Unit\_Price\>100.00\</Unit\_Price\>\<Shortcut\_Dimension\_1\_Code\>S10\</Shortcut\_Dimension\_1\_Code\>\<Shortcut\_Dimension\_2\_Code/\>\<Description\>Discounts\</Description\>\</Sales\_Invoice\_Line\>\</SalesLines\>\</SalesInvoice\>\</SalesInvoice\_List\>\</CreateMultiple\>  
\</soap:Body\>_  
  
It means that the system is trying to create a Sales Invoice using a manually defined number (e.g., \<No\>LV00001\</No\>), but the No. Series assigned (AA-INV) does not allow manual number entry. Business Central or NAV expects to auto-generate the number instead.&nbsp;  
  
You have two options to resolve this:

1. Remove the \<No\> field from your request payload.  
&nbsp; &nbsp; - Business Central or NAV will then auto-assign the next available number from the 'AA-INV' series.

2. Enable Manual Numbering in Business Central or NAV (requires admin access):  
&nbsp; &nbsp; - Go to 'No. Series' in BC.  
&nbsp; &nbsp; - Locate the 'AA-INV' line.  
&nbsp; &nbsp; - Tick the checkbox for 'Manual Nos.'  
  
Unless there's a business requirement to control invoice numbers externally (e.g., syncing with Salesforce or another system), we recommend using Business Central's or NAV's auto-numbering for consistency and to avoid duplicate or conflicting values.  
&nbsp;  
&nbsp;If you must set your own numbers, coordinate with the BC administrator to ensure proper setup of the No. Series.