# GCP´s not verified
**URL:** https://community.pix4d.com/t/gcp-s-not-verified/21606
**Category:** PIX4Dmapper
**Created:** [February 24, 2022, 10:53pm UTC](https://community.pix4d.com/t/gcp-s-not-verified/21606 "2022-02-24T22:53:25Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@MoniPalacios](https://community.pix4d.com/u/MoniPalacios)
#### Post date: [February 24, 2022, 10:53pm UTC](https://community.pix4d.com/t/gcp-s-not-verified/21606/1 "2022-02-24T22:53:25Z")
Hello everyone! I´m having trouble when merging projects. I´ve divided 10 km in 4 flights and processed them individually. Everything was right with eacho of them. But when I merged flights some of the GCP´s appear as not verified. I´ve checked the coordinates and they´re correct. I have no idea why the GCP´s are right in the individual project but when merging they´re not verified
[V3\_V4\_report.pdf](https://community.pix4d.com/uploads/short-url/61T0H4F6Ch9MPtSfe6LseJoWjEO.pdf) (460.0 KB)
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### Author:  [@Nikoleta\_Dimopoulou](https://community.pix4d.com/u/Nikoleta_Dimopoulou)
#### Post date: [February 28, 2022, 3:16pm UTC](https://community.pix4d.com/t/gcp-s-not-verified/21606/2 "2022-02-28T15:16:36Z")
Hi,
Can you share with us the individual quality reports of the 2 subprojects?
Have you followed all the steps described in the following article?
> **[How to merge projects](https://support.pix4d.com/hc/en-us/articles/202558529-How-to-merge-projects)**
>
> It is possible to merge projects for which step 1. Initial Processing has already been completed in Pix4Dmapper. This allows the combination of information from different projects into one single...
Please keep in mind that you need to identify and mark a minimum of three manual tie points (MTPs) that **have the same name** and point to the same feature on both of the projects.
Best,