The former couple - who split in late December after just two months together following a huge argument while on holiday in the British Virgin Islands - will both attend the event after managing to narrowly avoid each other at the NRJ Awards in Cannes, France last month.
A source told the Daily Mirror newspaper that the duo are preparing for an awkward run-in at the ceremony in London's O2 Arena on February 20.
Harry, 19, will be performing his new Comic Relief single 'One Way Or Another' alongside his One Direction band mates, who are up for Best British Group.
'I Knew You Were Trouble' singer Taylor, 23, is also in talks to perform after confirming she will attend the event, where she is nominated for best International Female Solo Artist.
Taylor has reportedly written five new songs about Harry since their dramatic split.
The country singer - who has previously dated Conor Kennedy, Taylor Lautner, Jake Gyllenhaal and John Mayer - is said to be heartbroken despite making a point of avoiding Harry at the NRJ Awards by delaying her arrival by 25 minutes so they wouldn't have to share the red carpet.
A source said: "It was very carefully timed so they didn't do the carpet at the same time.
"Taylor didn't do any backstage interviews and didn't use a dressing room - she changed at the hotel because she didn't want to see Harry at any point. ...Things were timed to keep them apart and for it to not become a big media circus."