Tom Waterhouse can't be Carl King's son Thomas King Junior as Tom Waterhouse told Debbie Dingle on the way to their burger van date back on Monday 18th September episode that he was way too young when his parents died.
so Tom Waterhouse has to be either or below ...
1: Tom Waterhouse could be Joseph Tate {half brother to Noah Tate nee Dingle and Noah is half brother to Debbie Dingle hence why Tom didn't want to meet Charity in case she recognized him} Joseph Tate's character on the show was given a birth date of Thursday 8th June 1995, he would have been 5 days old when he first appeared on the show back on Tuesday 13th June 1995. Joseph Tate would have been aged 8 when his on screen father Chris Tate was killed off on screen on the show back on Thursday 18th September 2003. Joseph Tate would have been aged 3 when his on screen mother Rachel Hughes was killed off on the show back on Wednesday 12th May 1999. IF Joseph Tate was still on the show now he would be aged 22.
2: Tom Waterhouse could be James Tate {son of Frank & Kim Tate}, James Tate was given a on screen character birth date of Tuesday 24th September 1996, he would have been aged 1 year old when his on screen father Frank Tate was killed off on screen on the show back on Tuesday 27th May 1997, as far as we know his on screen Mother Kim Tate is still alive but hasn't been seen on the show since her exit back on Tuesday 19th January 1999.
I think however we can rule out Tom Waterhouse being the following people below ...
Thomas King Junior {son of Carl & Collen King}, Character Date Of Birth: Friday 6th September 1996, 1st appearance: Friday 6th February 2004, Last appearance: Monday 8th April 2013, , if still on the show now he would be aged 21 -- he was aged 16 when his on screen father was killed off the show on screen back on 18th October 2012 and as far as we are aware his on screen mother Collen King is alive and living in Saudi Arabia
Max King {son of Tom King snr & Mary King}, Character Date Of Birth: Thursday 8th November 1979, 1st appearance: Monday 3rd January 2005 , Last appearance: Friday 30th September{aged 25}, if still on the show now he would be aged 38
Matthew King {son of Tom King snr & Mary King} Character Date Of Birth: 28th October 1970, 1st appearance on the show: Thursday 4th March 2004{aged 33}, Last appearance: 16th December 2008{aged 37}, if still on the show now he would be aged 47
Carl King himself {son of Tom King snr & Mary King} Character Date Of Birth: Thursday 19th July 1973, 1st appearance on the show: Friday 6th February 2004{aged 30}, Last appearance: Thursday 18th October 2012{aged 39}, if still on the show now he would be aged 44
Liam Hammond {son of Frank Tate as well as and half brother to Chris Tate, Zoe Tate and James Tate} Character Date Of Birth: Wednesday 9th August 1961, 1st appearance on the show: 31st August 1999{aged 38}, Killed Off Last appearance: 12th November 1999{aged 38}, if still on the show now he would be aged 56