Compare the overall cost, not just the headline interest rate, including arrangement fees, valuation charges, legal costs, cashback and any early repayment charge. Check whether each provider’s lending criteria, affordability assessment and maximum loan-to-value fit your circumstances, as the cheapest deal may not be available to you. Consider how long the rate is fixed, what happens when it ends, and the provider’s reputation for communication and service. An FCA-authorised mortgage adviser can help you compare suitable deals and explain the implications of each option.