Summarise Changes to My Pay After a Pay Rise and Tax Band Shift

A pay rise arrives and it is not obvious how much of it survives tax, National Insurance, and any threshold you might have just crossed, including ones that quietly claw back benefits. This works out the real take-home increase and flags whether extra pension contributions could keep you on the right side of an unfavourable taper.

<context>
You received a pay rise that pushes you close to or over a tax band threshold. Old salary: {OLD_SALARY}. New salary: [new salary].
</context>

<task>
**Summarise**:
1. Whether the rise pushes any portion of income into a higher tax band
2. The actual take-home increase after tax, National Insurance, and any benefit tapering (such as the personal allowance taper or child benefit charge, if relevant)
3. Whether increasing pension contributions could avoid crossing an unfavourable threshold
</task>

<output_format>
- Before and after take-home comparison
- Plain statement of whether a threshold is crossed and its effect
- One practical option to consider if a taper applies
</output_format>