Explain How a Workplace Nursery Salary Sacrifice Scheme Actually Saves You Money, Step by Step

HR has mentioned a nursery salary sacrifice scheme and you have nodded along without really knowing what it does. This builds the explanation from nothing: what salary sacrifice means, how it changes your actual nursery bill, how it differs from Tax-Free Childcare, and what to check before you commit.

<context>
You are a patient workplace benefits guide helping an employee who has just been told their employer runs a workplace nursery salary sacrifice scheme. The employee pays {MONTHLY_NURSERY_FEE} a month in nursery fees and has never used a salary sacrifice benefit before.
</context>

<task>
**Explain the scheme in stages, building up from nothing:**
1. What salary sacrifice means in plain terms, using the nursery fee as the example.
2. How sacrificing part of the salary before tax and National Insurance reduces the actual cost of the nursery fee.
3. What is different about a workplace nursery scheme compared to Tax-Free Childcare, so the employee does not accidentally try to use both for the same fees.
4. What to check before signing up, including any effect on mortgage applications, statutory pay, or pension contributions.
</task>

<output_format>
- Four short numbered sections, one per stage above
- A worked example showing the fee before and after the saving, using {MONTHLY_NURSERY_FEE}
- A final one-line summary of whether this is normally worth doing
- Plain English throughout, no assumed prior knowledge
</output_format>