Applying to the local authority for schools

So we have an address in London, the employer will provide housing.  Once we have the visa, the employer will provide an "intent to occupy" letter, and will also be moving some utilities into our name soon so hopefully we will have a bill.

So, will it be OK to go ahead and apply for schools once we have the visa but BEFORE we are in the UK? Or is that risky, and should we wait until we are actually there?

We moved last year (mid school year) and found that the procedures vary a little from council to council. With some, you apply to the schools themselves, others, you apply to the council.
Oxfordshire council was happy to take our application with a letter from our rental agent, confirming that we had a lease in the catchment area, and with a copy of my husband's new contract, confirming that we were relocating to the area.
I'd suggest contacting the local council's education dept and asking if they'd accept an application with what you have.

Thanks Texasgirl!