Self employment now ended HMRC question

Hello folks,

I used to do some self-employed work but this has now ended (last month) and all of my salary will be under PAYE and is entirely different.

It's not very likely that I shall do any self-employed work again, but not impossible - but certainly not in plans. It was around £1500 a year gross.

Can I de-register from HMRC after my last tax return so that I don't spend years filling out tax returns on no income? I was a sole trader as it were. Not a company. Do I need to let them know sooner? I could continue this year to be registered but seems pointless and poss dishonest given that I am not seeking new contract to replace old work and would be entitled to claim costs if I stay registered.

Many thanks.