Refinancing your mortgage can have a small, temporary impact on your credit score. Here's how refinancing can affect your credit score:

- Refinancing can result in a hard credit inquiry, which can cause a small, temporary drop in your credit score. This is because credit bureaus view applying for a new loan as a sign that you might be overextending yourself financially.

- Refinancing can also affect your credit score by replacing your old debt with new debt. This is because older, established debts are considered more valuable than new debts, even if you're making payments for the same asset.

- Refinancing can also cause a small, temporary drop in your credit score due to the credit utilization ratio. This is because taking on a new loan can increase your credit utilization ratio, which can negatively impact your credit score.

However, it's important to note that the impact of refinancing on your credit score is usually small and temporary. As long as you make your payments on time and keep your credit utilization ratio low, your credit score should bounce back within a few months.