# Question regarding the UUID, ICV and Timestamp

**URL:** <https://zatca1.discourse.group/t/question-regarding-the-uuid-icv-and-timestamp/4687>\
**Category:** General\
**Created:** [December 19, 2024, 9:35am UTC](https://zatca1.discourse.group/t/question-regarding-the-uuid-icv-and-timestamp/4687 "2024-12-19T09:35:11Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![idrees](https://avatars.discourse-cdn.com/v4/letter/i/58956e/32.png) [@idrees](https://zatca1.discourse.group/u/idrees)\
**Post date:** [December 19, 2024, 9:35am UTC](https://zatca1.discourse.group/t/question-regarding-the-uuid-icv-and-timestamp/4687/1 "2024-12-19T09:35:11Z")

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Salam,  
A similar question is already answer here:  
[Question regarding the UUID, ICV and IRN](https://zatca1.discourse.group/t/question-regarding-the-uuid-icv-and-irn/1307)

But I need some more clarification on this.

 ![image](https://europe1.discourse-cdn.com/flex013/uploads/zatca1/original/1X/4d2dbe3b2bc80ffe06a271daf90d07254139c36c.png)

1- **cbc:ID** This is system-generated InvoiceNo in EGS. and this should be unique.  
Lets say I have an InvoiceNo = INV001 (or **cbc:ID** ), if it is success, this value should not be repeated.  
If this invoice is rejected for any errors, and I need to create and re-send the same Invoice(invoice content). Now in this new request, should I use the same InvoiceNo=INV001 or it would be INV002 in this case?

1. Same question - What will be the case of if request is rejected/failed.
2. Same question.
3. I read somewhere on this same portal, the timestamp should also be unique for each invoice. Please elaborate this also.