# Common errors and fixes This page covers the most common problems You might run into when creating, sending, or importing sales invoices in Fitek - and how to fix them. *** ### I can't create or save the invoice #### "Mandatory fields missing" - the invoice won't save When You click **Create Sales invoice**, Fitek requires all mandatory header fields to be filled: Customer, Invoice date, Due date, Document type, Currency, and Language. **How to fix:** Fill in all mandatory header fields. If Currency or Language aren't pre-filled, select them manually - they may be missing from the customer profile or company defaults. *** #### The customer is missing from the dropdown The Customer field pulls from Your saved customer list in **Settings → Customers**. **How to fix:** Add the customer first. Make sure the customer profile has at least Name, Country, and VAT NO or REG NO. See [Managing customers](/sales-invoices/getting-started/managing-customers.md) for details. *** #### Due date is not accepted or keeps changing Fitek calculates the due date automatically: Due date = Invoice date + Payment terms (in days). The due date cannot be earlier than the invoice date. **How to fix:** Set the invoice date first, then adjust the due date. If payment terms are wrong, update them on the customer profile (preferred) or in **Settings → Company Settings**. *** #### "Additional information" is rejected The Additional information field is limited to 500 characters. **How to fix:** Shorten the text, or move longer notes to an attachment or Your internal communication. *** ### I can create the invoice, but I can't send it #### "Send e-Invoice" button is missing Fitek only shows the Send e-Invoice button when the invoice status is **Unsent** or **Delivery issues**. For details on what each status means, see [Understanding statuses](/sales-invoices/getting-started/understanding-statuses.md). **How to fix:** Check the invoice status. If it's **Sent**, the invoice has already been submitted. If it's **Import issues**, fix the problems first (see [Import via API](#imported-invoice-shows-import-issues) below). *** #### Validation pop-up: "e-Invoice has not been sent" When You click **Send e-Invoice**, Fitek runs a pre-sending validation on the invoice rows. If validation fails, Fitek shows a pop-up, highlights missing fields, and shows tooltips when You hover over them. The most common row problems: **No invoice lines**\ Add at least one invoice line. **Line missing required data**\ Each row needs: Description, QTY, Unit, Price, VAT type/category, and VAT %. Fill all required fields on every line You intend to send. **Unit of measure can't be typed freely**\ For e-invoicing, units must come from the supported list (no free text). Choose a unit from the dropdown. **VAT type / VAT % issues**\ VAT types are selected from a controlled list. If VAT type is Exempt or No tax, VAT % becomes read-only and is set to 0 automatically - this is expected. Choose the correct VAT type and make sure VAT % is present where required. *** ### I sent the invoice, but it shows "Delivery issues" After sending, the e-invoice network may reject the receiver or the invoice content. Fitek will show status **Delivery issues** along with the actual error message returned by the network. *** #### "Customer not found in the e-invoice network" This usually means the customer doesn't receive e-invoices via that network, or the customer identifiers are wrong (typically Country + VAT/Registration number). **How to fix:** Open the customer profile and verify Country, VAT NO or REG NO, and customer name. Ask Your customer for the exact legal identifier they use for receiving e-invoices. Check the [Peppol directory](https://directory.peppol.eu/) to confirm Your customer is registered in the Peppol network. *** #### "Invoice data missing/invalid" (rule or format errors) The e-invoice network can apply additional rules that may not be fully validated in advance by Fitek. **How to fix:** Open the invoice details and read the error message block. Correct data (often contact details, addresses, identifiers, or line-level VAT/unit details). Then re-send - invoices with status **Delivery issues** can be sent again. *** ### Imported invoice shows "Import issues" This applies to invoices imported via PDF or API. **Import issues** means required attributes are missing or values are invalid. **How to fix:** * Open the invoice and check which fields are marked as incorrect or missing * If Your workflow is "create in ERP → import to Fitek," correct the data in the source system and re-import * Use the Export report (filter by problematic statuses) to review issues in bulk *** ### Quick status reference For a full explanation of each status and what to do about it, see [Understanding statuses](/sales-invoices/getting-started/understanding-statuses.md). Here's a quick overview: * **Unsent:** created or imported and ready to send * **Sent:** submitted for delivery * **Delivery issues:** rejected or failed delivery; fix data and retry * **Import issues:** imported with missing or invalid data; fix before sending --- # 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://fitek-learning.fitek.com/sales-invoices/troubleshooting/common-errors-and-fixes.md?ask= ``` 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. 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