Self Assesment needed for savings/salary?

I wonder if anybody might be able to advise, as I’m getting myself very confused on what I need to do with about my tax. I am employed and pay tax through PAYE, I always have, so have never had to deal with tax before. I have always been a basic rate taxpayer. My personal situation changed massively earlier this year and I am now in receipt of a Widowers Pension from my wife’s employer. With this and my salary together I will be about 5k under the 50k annual threshold, so shouldn’t be paying the higher tax rate on this income. I did however also receive a tax-free lump sum. All my savings are in high street banks, and I anticipate the annual interest on my savings to be between 10-15k. So… do I need to complete a self-assessment tax return, I assume I do? I have received mixed advise on whether I do or don’t. I spoke with HMRC earlier in the year and was told I don't, the banks will inform HMRC, who will then work out what tax is required and adjust my tax code accordingly (i think that's what they said). However, at the time I was still very much in the depths of grief and I may not have been explaining my situation very well. It has also been suggested to me that I very much do need to complete a self assessment form, and that I would be well advised to get an accountant to do it. So I'm very confused on what I should be doing when next April comes around.

I would advise going through this to check if you do need to or not: https://www.gov.uk/check-if-you-need-tax-return

Hi REP

Due to the level of investment income you expect to receive, yes you will now need to complete a tax return. investment income over £10k meets the criteria so if you had this for 22/23 then you will need to do a return for that year.
If it is only from the 23/24 year, you can register up to 5/10/24 to avoid any late penalties - Self Assessment tax returns

Thank you

Thank you, I appreciate getting some clarity on that!