If you need to upgrade your code to be compliant to PHP version 7, and your code is still on 5.4 or 5.6 or even below that, I can upgrade it to be compliant to new version 7.
For WordPress websites, before you request for an upgrade, try and do the following:
Make sure WordPress website is updated (Check version running and compare to latest version)
Make sure all plugins and themes are up to date. Go to plugins page and update every plugin that needs to be updated.
Install PHP Compatibility Checker Plugin, and activate it.
Run Scan to check for compatibility with PHP 7.0 or above
Get the log and see if there are any compatibility issues pointed out
From the report, if there are any plugins/themes that show errors, then contact me with the report downloaded as text file.