Your fuel supplier will give you the specs required.
If you do not meet the specs, they are unlikely to drop fuel.
It is not that hard, have done one before.
From memory, the tank had to have the capacity to be inspected (ie a manhole), had an approved lining applied by an accredited applicator, and a breather.
There ends the suppliers interest. Where and how it gets into your aircraft then becomes the interest of the regulator. Again, not that hard.
The tank we did was about 2000lt, do not recall that it required bunding, but that may have changed.