You may be subject to the Tapered Annual Allowance and this restricts the amount of contributions that are eligible for tax relief. This relies on your “threshold income” and “adjusted income”.
If your threshold income is over £200,000 and adjusted income is over £260,000, your annual allowance reduces by £1 for every £2 over £260,000 down to a minimum annual allowance of £10,000. Threshold income is taxable income including earnings and investment income less pension contributions and certain other allowances.
Adjusted income is taxable income with pension contributions and certain other benefits added.