What wage is a decent wage these days?

Her own mother spends more, married into money and has never worked a day in her life.
I live alone in London on less than £30 a week after rent & bills, working three jobs and weekends.
It all depends on lifestyle choices and standard of living.

Would you really expect to be able to buy a London house, pay for a wedding and have more than one child on a household income of £18k after tax (1500 x 12)?

Well I get by with £800 a month in Northern ENgland. it's an absolute skimp of a lifestyle but I don't care too much about possessions. plus im a broke student and i will never be able to drive so my costs are significantly lower than other people.

Her own mother spends more, married into money and has never worked a day in her life.
I live alone in London on less than £30 a week after rent & bills, working three jobs and weekends.
It all depends on lifestyle choices and standard of living.

Would you really expect to be able to buy a London house, pay for a wedding and have more than one child on a household income of £18k after tax (1500 x 12)?

to be honest a salary of £90k looks appropriate to achieve all of that

Rather you than me- in London.
I won't be able to afford the financial costs of providing for more than one child, so can only have one.
Wouldn't risk buying a London house, paying for a London wedding and raising a child on an income below £110k.

Say a mortgage deposit of 10-15%, mortgage lenders loan-to-borrow income ratio usually capped at 450% of annual salary and the 28/36 rule (maximum of 28% of income on housing costs, 36% on total debt service- including mortgage, credit cards, overdraft, student loans, car finance).
Average wedding cost in 2018 was over £30k according to the National Wedding Survey run by BrideBook.
None of the London wedding planners I know accept clients with a combined wedding booze and flowers budget below £40k.

My mother came from a very affluent background.
She has had a taste for the high life since childhood, is in the habit of giving expensive gifts/loans/handouts to a variety of pals and activist causes.
Possible addictions include: activism, bizarre choice of mostly deranged/vicious pals, charity, contrarianism mixed with non-sexual masochism, encouraging illegal immigration, fortnum & mason, harrods, luxury brands, revolutionary politics, trying to buy herself friendship to compensate for a lonely childhood and habitually giving money/freebies & the time of day to those who least deserve it.

My father is a total skinflint, in the habit of collecting coupons and getting refunds for almost all birthday gifts he receives (solely to chuck the money in the face of the gift giver).

I dunno, i feel like your mother has rubbed off on you! For example, you automatically assume you're going to hire a wedding planner. I'm pretty sure only rich people and idiots hire wedding planners.

Buying a house is a huge problem, but that's why everyone lives with their parents until they're 35 then lives in the **** areas.

Her own mother spends more, married into money and has never worked a day in her life.
I live alone in London on less than £30 a week after rent & bills, working three jobs and weekends.
It all depends on lifestyle choices and standard of living.

Would you really expect to be able to buy a London house, pay for a wedding and have more than one child on a household income of £18k after tax (1500 x 12)?

why would your mother swipe your life savings if she is rich?

it sounds like you've inherited your mothers expensive tastes for things as 200k+ is way over the top for raising a family [even in London]

Would you really try buying a house in London, paying for a wedding and maintaining at least one child on an income below £110k?

1. no need to have a big wedding just sign a paper costing £50-£200 saying that you are married
2. no need to buy a house, flats/apartments exist plus worse case scenario you can rent a house
3. no need to have more than one child either

Plenty of people do it in London.

probably less than 10% of the population in London has a combined income of greater than 110k ....yet there are still people buying homes and raising families....

and if you do really need 110k, then I suggest you move, I know your name is LondonMyst ....but you'd be much better off becoming a LiverpoolMyst or something like that .....because I doubt you are gonna obtain this 110k annual figure unless there's something you're telling me.

you are working 4 jobs and have £30 spare at the end of each week.

My answer to OP was based on OPs scenarios: buying a house, getting married and having kids.

Personally, I wouldn't have my wedding in a registry office.
Nor a big wedding or large number of guests.
But I would spend money on a church, rings, wedding outfits including the bridesmaids, party and catering for the guests.

still don't think that one need's £225K in order to have a family in London

Many professional Londoners are walking a financial tightrope struggling to keep up with the Joneses, Smiths or Shahs.
Living the high life on credit; car finance, expensive hire purchase deals, high mortgage costs, installing £20k kitchens and then chucking them after 3-4 years.
Others are relying on welfare funds to feed, house and pay for childcare for their household.

Living costs in London are very expensive and rents notoriously exorbitant.
But I love London life.
I'm none too keen on relocating to regions of England like Liverpool, Manchester, Newcastle, Nottingham, Yorkshire or the countryside.
I have considered moving to Belfast.

I mean if they are the only one with salary, that makes some sense. A couple will earn £100k each, which is reasonable.

yes but it's not what you "need". £80K per parent before tax in enough imo.

Well yeah, but I think a bit extra for saving, investing, hobbies and other miscellaneous for a comfortable life is part of 'a decent wage'. You can scrape by with much less and can struggle with much more anyway.