In pay slips of our client(i.e.company), name of our another client(i.e. company) is showing instead of our actual client's name, kindly suggest solution of it.

Thanks for coming here, malichowhan.

It's possible that a wrong company file is opened. Make sure to log in to the correct QuickBooks Online (QBO) account where you want to create paychecks.

If it's the correct account you're logging in to, you'll want to review the Audit Log history to check if someone made changes to the client information reason why it's showing another client's name.

To do that:

1. Go to the Gear icon and select Audit Log.
2. Select Filter.
3. Use the fields on the Filter panel to choose the appropriate User, Date, or Events filter to narrow the results.
4. Click Apply.

Learn more about using the Audit Log Feature through this article: Use the audit log in QuickBooks Online. 

Once verified, you can correct the client's name on your Accounts and setting page. I'll show you how to do it below:

1. Go to the Gear icon and choose Account and settings.
2. Click the Company tab.
3. From the Company name section, click the Pencil icon.
   
4. Enter the correct name. Click Done.

Learn more about managing company information through this article: Edit company settings in QuickBooks Online.

I'm still here whenever you have questions with QBO. Have a wonderful day ahead.