Title: Invoice Number not sequential
Last modified: February 23, 2021

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# Invoice Number not sequential

 *  [parale3000](https://wordpress.org/support/users/parale3000/)
 * (@parale3000)
 * [5 years, 3 months ago](https://wordpress.org/support/topic/invoice-number-not-sequential/)
 * We have an issue that in some cases the number of the invoice skip some numbers.
   We have already check the forums but we dont have find similar problem to this.
   Do you have any idea how we can solve this problem?

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Thread Starter [parale3000](https://wordpress.org/support/users/parale3000/)
 * (@parale3000)
 * [5 years, 3 months ago](https://wordpress.org/support/topic/invoice-number-not-sequential/#post-14091003)
 * We have already seen a few threads mentioning that the issue was because there
   were cancelled or refunded orders that were taking up numbers but we didnt have
   any cancelled or refunded orders.
 * Are there any known issues why your plugin skips invoice numbers and is there
   a fix in place or something to try?
 *  Plugin Contributor [Ewout](https://wordpress.org/support/users/pomegranate/)
 * (@pomegranate)
 * [5 years, 3 months ago](https://wordpress.org/support/topic/invoice-number-not-sequential/#post-14091224)
 * If you have set the ‘Display invoice number’ setting ‘Invoice Number’ (‘Order
   Number’ could also cause gaps, see: [Why is the PDF invoice number different from the WooCommerce order number?](https://docs.wpovernight.com/woocommerce-pdf-invoices-packing-slips/invoice-numbers-explained/#why-is-the-pdf-invoice-number-different-from-the-woocommerce-order-number)):
   
   And you indeed have no cancelled/refunded or deleted orders, then there are only
   a few possibilities left:
    1. The ‘missing’ invoice numbers are assigned to (much) older orders
    2. There is a so called ‘race condition’ affecting your setup. This is mostly caused
       by payment providers, a well known example is for PayPal: if you have setup 
       PayPal with payment confirmation by both IPN and PDT, PayPal will send duplicate/
       concurrent confirmations, resulting in emails being sent twice, stock being 
       reduced twice… and invoices being created twice (only 1 survives).
 * Can you confirm any of the above?

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘Invoice Number not sequential’ is closed to new replies.

 * ![](https://ps.w.org/woocommerce-pdf-invoices-packing-slips/assets/icon-256x256.
   png?rev=2189942)
 * [PDF Invoices & Packing Slips for WooCommerce](https://wordpress.org/plugins/woocommerce-pdf-invoices-packing-slips/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/woocommerce-pdf-invoices-packing-slips/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/woocommerce-pdf-invoices-packing-slips/)
 * [Active Topics](https://wordpress.org/support/plugin/woocommerce-pdf-invoices-packing-slips/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/woocommerce-pdf-invoices-packing-slips/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/woocommerce-pdf-invoices-packing-slips/reviews/)

 * 2 replies
 * 2 participants
 * Last reply from: [Ewout](https://wordpress.org/support/users/pomegranate/)
 * Last activity: [5 years, 3 months ago](https://wordpress.org/support/topic/invoice-number-not-sequential/#post-14091224)
 * Status: not a support question