A locked phone refuses any SIM but the one from the operator that sold it. The eSIM will install perfectly well — it just will not connect.
Operators that sell handsets on contract or instalments lock them to their own network until the balance or the term is finished. The hardware is fine and may well support eSIM — it is simply programmed to refuse any other network.
The confusing part is that the eSIM installs and appears in Settings as normal, and only then shows “No service” or “SIM not supported”. The lock is the problem, not the plan.
On iPhone — the clearest route:
On Android:
In every case the operator you bought the handset from can tell you definitively.
Be wary of paid “unlocking” services online — many are scams, and some void the warranty or simply re-lock after the next update.
An unlocked phone that cannot take an eSIM is no use either. Check that your phone supports eSIM — it takes under a minute.
Once the eSIM has been installed it cannot be returned, which is why we ask you to confirm before paying. If you have not installed it yet, contact us straight away and see the refund policy.