Prevent browsing to sub domain

For starters, your rewrite rules are a mess. Try just using:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress

as a proper foundation. Any additional rules should be added before the # BEGIN WordPress line.,

Thanks esmi.
I had been playing with a plugin which upset my htaccess file.

Where would I place the following?
RedirectMatch 404 /\\subdomaina(/|$)

Before the # BEGIN WordPress line.

I read that instruction in your previous post but get a 500 error.
Is there something wrong with the first line?

RedirectMatch 404 /\\subdomaina(/|$)

# BEGIN WordPress
<IfModule mod_rewrite.c>

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

Can anybody please advise if there is something wrong with this line?

RedirectMatch 404 /\\subdomaina(/|$)

where subdomaina is a directory?

What are you trying to do with that line?

Thanks for your reply esmi. I want to prevent access to subdomaina from mydomain

mydomain.co.uk/subdomaina redirects to mydomain.co.uk unless loaded through a browser as www. subdomaina.co.uk

Try:

RewriteCond %{HTTP_HOST} ^mydomain\.co\.uk/subdomaina$ [NC]
RewriteRule ^(.*)$ https://mydomain.co.uk [R=301,L]

Thanks very much.

I have added that but still it doesnt work. I even tried adding a forward in the host control panel but neither work.

Heres your version with actual domains:

RewriteCond %{HTTP_HOST} ^kcpackaging\.co\.uk/polycover$ [NC]
RewriteRule ^(.*)$ https://kcpackaging.co.uk [R=301,L]

# BEGIN WordPress
<IfModule mod_rewrite.c>

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

Heres the hosts version which is what messed everything up originally after adding re-directs through control panel:

rewriteengine on
rewritecond %{HTTP_HOST} ^www.kcpackaging.co.uk$ [OR]
rewritecond %{HTTP_HOST} ^kcpackaging.co.uk$
rewriterule ^polycover$ "http\:\/\/kcpackaging\.co\.uk\/" [R=301,L] #50ad27faa46d2

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteBase /
</IfModule>
# END WordPress
rewriterule ^index\.php$ - [L]
rewritecond %{REQUEST_FILENAME} !-f
rewritecond %{REQUEST_FILENAME} !-d
rewriterule . /index.php [L]

https://www.kingscooty.com/blog/redirect-a-subdomain-to-a-main-domain-using-htaccess/
https://stackoverflow.com/questions/1321123/redirect-from-subdomain-to-domain-htaccess

Well thanks for all your help esmi, but still not working!

Im not sure if the directories would be classed as sub domains or rather just sub directories.

Reading up on a post written by Jeff Starr on Perishable Press I found this article talking about RedirectMatch. It now works a treat but still puzzled as to why all the others did not work. Thanks again for your help.