Deceased self assessment

My husband completed a self assessment for 2022-2023 in Dec 23. He passed away in February 2024 and I have completed a final self assessment for him for 2023-2024. I have since received a letter from hmrc advising how much refund is due but I have also received payment from hnrc into my bank which is more than the letter states. Could this refund include last year's rebate as I'm unsure if a refund was offered due to closure of his bank account?

Hi LaineyJ Coombe,
To help us to explain this payment, we would need to review your husband's record.
Please contact us by webchat or phone here:
Self Assessment: general enquiries
To allow us to do this.
Thank you.