There can be the odd exception for both houses and for commercial use, But in the vast majority of cases, single phase means a maximum of 100 amps.

Some DNOs will under some conditions allow 125 amps single phase, but this is the exception and not the norm.

If 100 amps or exceptionally 125 amps is not enough, then 3 phase is the norm. If three phase is not available, then single phase 3 wire, often called split phase is a possibility.

In extreme circumstances the only options  may be, move, use a generator, or switch the larger loads to solid fuel, oil, or gas. That is rare.

broadgage said:

then single phase 3 wire, often called split phase is a possibility.

Careful how you handle this, though, as U = 460 V not U = 400 V (Usually OK for cables, but products or assemblies containing or connecting to circuits from both phases can be interesting).

broadgage said:

then single phase 3 wire, often called split phase is a possibility.

Careful how you handle this, though, as U = 460 V not U = 400 V (Usually OK for cables, but products or assemblies containing or connecting to circuits from both phases can be interesting).