The school needs to spend £6K before you can apply for an EHCP

No this is not accurate. The legal threshold contained in Section 36 (8) of the Children and Families Act 2014 does not require that the school spends £6,000 before you can apply for an EHC needs assessment. If you receive a refusal to assess where this is stated, the LA has applied a higher level criteria to its decision-making which would not be a lawful reason to refuse.