Best way to inform UC if changes happen as dont have a online journel

Hi there , its nit defi ate but my adult daughter may move in with me later this year , If she does how do i go about informing uc ? I dont have a online journel so would have to be by phone , or email , letter ? Which is the best way , have had some very up and down info by phone before lol so maybe better by mail to a head office ? Many thanks x

Thank you david , i do have weeks as if she does move back to this area she wont be for a month or more , im tempted to phone uc but have had a bad experience when i had to change my phone number ( not my choice ) then i had a phone call due with job centre soon after and the telephone uc adviser didn't send the info correctly she had the numbers wrong ! So it was a mess , il have to have a think . Many thanks .