At some point in his life, Phil met Vanessa at a park which is briefly mentioned in Season 2 Episode 8 in one of James' flashbacks. Phil had a son with Vanessa and named him James. After James' mother committed suicide, he tried to stay positive by acting optimistic but at the same time, would consume a lot of unhealthy food which eventually lead to a fatal heart attack.
The first appearance of Phil is in Season 1, Episode 1 in a flashback where he tells 8 year old James a joke but James doesn't laugh at the joke. When Alyssa goes to James' house for the first time, Phil returns home and sits at the kitchen table with them [Alyssa and James]. He makes things awkward when he jokes about thinking James was gay and is quickly shutdown by Alyssa's stubborn attitude.
At the end of Season 1, Episode 1 when James and Alyssa are leaving James' house, Phil appears in the driveway, having returned from the grocery store. As he walks towards James, James punches him in the face hard enough to knock him out and make him fall to the ground.
In Season 1, Episode 2, we briefly see him watching TV while putting a frozen bag of peas to the spot where James punched him. Another brief appearance occurs in the same episode where he's presumably giving younger James advice about being a man. In the final scene of the episode, he is calling the police presumably to search for James which is confirmed in Season 1 Episode 5.
In Season 1, Episode 5, Phil is questioned by the police in his house. When asked why he didn't report the car missing when he reported James missing, he said, "I didn't want to get him into trouble. He's a weird kid but not bad." When asked about the bruise on his eye, he claims that he got into a fight at the pub and denies that James punched him presumably for the same reason he didn't report the car missing. When asked about James' mother, he reveals that she died and quickly changes the subject which means he is still affected by the suicide. At the end of the questioning, he tells the police that James was with a girl named Alyssa.
In Season 1, Episode 6, Phil is questioned again by police but this time it's about a knife they found that belongs to James. He reveals that the knife was given to James on his 13th birthday (which is probably why the knife has a 13 on it). One of the officers berates him for buying a hunting knife for a 13 year old to which he replies, "Well, he asked for it. Actually, no, he asked for a machete. But I said that was a bit full on." The other officer tells him that the knife was confirmed as a murder weapon in for the murder of Clive Koch which surprises Phil and makes him start defending James by saying, "He's weird, OK? But he's... he's not dangerous."
In Season 1, Episode 7, Phil is brought in along with Alyssa's parents and shown the security camera footage of the gas station that James and Alyssa had robbed. When asked where he got a gun from, Phil claims that he never had a gun and only a knife which causes Gwen to storm out of the room. He also brings up that James is turning 18 tomorrow and soon after, brings up that his wife killed herself and starts crying. This is the last appearance of Phil in Season 1.
For most of Season 2, Phil appears in James' flashbacks and in an urn of his ashes which James carries around for most of the season.
In Season 2, Episode 2, Phil visits James in the hospital where James is being treated for the bullet wound. Phil notices that James is not eating his food and asks if he can have it and when James allows him to have it, he eats it. It is also revealed in this episode that James' dad's way of coping with his son's tragedy was to "eat or cry" according to James. The episode also shows the result of the James' case and he was able to get off with a suspended sentence which excited Phil. James felt guilty about destroying his dad's car and wanted to pay for a new one but Phil declined the money and bought a new car with his own money. James reveals that Phil also took online parenting courses after he was shot and Phil started talking about his feelings more often. Phil expressed in that scene that he wanted to do more activities with James so they went bowling together. Phil throws the ball down the lane and gets a strike which he gets excited about. Unfortunately, after Phil celebrates his strike, when James goes up to bowl, Phil collapses due to a heart attack.
In Season 2, Episode 8, Phil describes in a flashback how he met James' mother. According to Phil, he was eating a sandwich on a bench and she was walking her nan's dog and it was "just like something out of a film". James dumps Phil's ashes which is now a sludge because some water was in the urn at the spot where Phil met Vanessa. This is the last time we see Phil referenced.
Phil's death is shown in Season 2, Episode 2, when he is bowling with James. Phil gets a strike and yells in excitement. As James is going to up to bowl, Phil collapses behind James which is revealed to be due to a heart attack presumably caused by eating an excessive amount of unhealthy food. After his death, it is assumed that Phil was cremated because James is carrying around an urn full of ashes for a majority of Season 2.
Phillip is portrayed in the television series, The End Of The F***ing World, by actor Steve Oram, who is most known for his roles in Sightseers, The World's End, and Aaaaaaaah!.