WHMCS Installation with utf8mb4 Database - Potential Issues & Best Practices

[centos777]

Hi everyone,

 

I'm setting up a new WHMCS 7.10 installation and have a question regarding database character sets. My server environment is configured to use utf8mb4, which I'd like to fully utilize for better Unicode and emoji support.

 

Here is my current situation:

 

WHMCS Version: 7.10

 

Database Character Set: utf8mb4

 

Database Collation (visible in phpMyAdmin): utf8_general_ci

 

WHMCS Configuration File: I have added $mysql_charset = 'utf8mb4'; to configuration.php.

 

Even with the database collation set to utf8_general_ci, I've noticed that I can still input and see 4-byte characters like 🚀 without any visible issues.

 

This is a bit confusing to me. I've read that utf8_general_ci is a 3-byte collation and might cause data corruption or truncation.

 

My questions are:

 

Is this "working" state (utf8mb4 database with utf8_general_ci collation) reliable for long-term use? Or is it a potential landmine for data corruption?

 

If it's not a good idea, what is the best way to convert my database and all WHMCS tables to utf8mb4_unicode_ci without breaking the installation?

 

Are there any known issues with a WHMCS 7.10 installation that has its database converted to utf8mb4_unicode_ci? For example, any problems with a future upgrade to a later WHMCS version?

 

I appreciate any insights or best practice advice from the community, especially from anyone who has gone through this process before.

 

Thanks in advance!

 

 

[Kian]

I asked about this a couple of weeks ago here, but they’re not planning to support utf8mb4 in version 9.0.

WHMCS is currently not designed, and likely will not be in the near future, to work with mb4. Even if you manually change all tables and columns, WHMCS might not recognize the new encoding, could overwrite your changes during updates or fail to perform queries on columns that store 4-byte characters such as emojis. There's also a significant risk of breaking internal queries, triggers or PHP functions that assume standard utf8. We can't see the code so who knows what is going on?

Furthermore, WHMCS could refuse to provide support for your installation, as these changes would make your database non-standard. This applies to third-party modules as well. I had the same idea but ended up discarding it. Not worth the risk.

[centos777]

Ah, got it — thanks for clearing that up!

Sounds like WHMCS just isn’t built for utf8mb4 yet, and forcing it might cause more trouble than it’s worth. I was mainly thinking about emoji and full Unicode support, but yeah, if it risks breaking stuff or losing support, I’ll pass for now.

I’ll stick with the default utf8_general_ci setup and hope they eventually add proper utf8mb4 support down the road.

Appreciate the heads-up!

Edited Wednesday at 02:28 PM by centos777

[centos777]

5 minutes ago, Kian said:

I asked about this a couple of weeks ago here, but they’re not planning to support utf8mb4 in version 9.0.

WHMCS is currently not designed, and likely will not be in the near future, to work with mb4. Even if you manually change all tables and columns, WHMCS might not recognize the new encoding, could overwrite your changes during updates or fail to perform queries on columns that store 4-byte characters such as emojis. There's also a significant risk of breaking internal queries, triggers or PHP functions that assume standard utf8. We can't see the code so who knows what is going on?

Furthermore, WHMCS could refuse to provide support for your installation, as these changes would make your database non-standard. This applies to third-party modules as well. I had the same idea but ended up discarding it. Not worth the risk.

thanks for clearing that up!Sounds like WHMCS just isn’t built for utf8mb4 yet, and forcing it might cause more trouble than it’s worth. I was mainly thinking about emoji and full Unicode support, but yeah, if it risks breaking stuff or losing support, I’ll pass for now.

Honestly, it’s kinda disappointing that WHMCS still doesn’t support utf8mb4 in 2026 — feels a bit outdated for a system like this.