First, a crucial one - in order to remove illegal immigrants, you need to be able to distinguish not just between illegal immigrants and legal IMMIGRANTS, but between illegal immigrants and legal CITIZENS.
Second fact you need to know is that this decision of distinguishing between illegal immigrants and legal citizens is not just taken once centrally, but, BY DESIGN it is to be taken by all landlords, healthcare providers, banks, employers, DWP, education establishments.
They all have to be immigration experts and check for illegal immigrants.
You can check EU citizens for EU passports (for now at least, that's enough).
You can check non-UK/EU citizens for e.g. proof of leave to remain.
But what about those who claim they're not EU or non-UK/EU?
So, to check the "non-foreigners", "one of us", "not one of them" category, there's a variety of acceptable documents - including a British passport (though note! the NHS guidance says that's not in itself enough for being eligible for NHS treatment), or birth certificate.
This is of course the group that includes the Windrush generation that thanks to the wonderful journalism of @ameliagentleman (who has been writing about this for MONTHS) most people are now aware of, and horrified about.
I think the answer lies in the fact that many service providers really struggle with these complex guidances. They may want to ignore them altogether. But the fines are scarily high if they "knowingly" employ / let to illegal immigrants, and the NHS is under financial pressure.
"27% [of landlords] are reluctant to engage with those with foreign accents or names. Checks are not being undertaken uniformly for all tenants, but are instead directed at individuals who appear ‘foreign’."
In the Netherlands (and other countries, but I'll talk about the one I know about), everyone registers with the community you live in. If you move from say Rotterdam to The Hague, you deregister from Rotterdam, and then you re-register in The Hague.
So, in the Netherlands they can check easily whether someone is entitled to work, rent, healthcare etc. Really easy. Landlords, employers, healthcare providers don't have to be immigration experts. There's no "them and us". EVERYONE is on the register.
Excellent thread, clearly explained. Like everyone else, I had to register locally in Germany & Netherlands when I lived there, also in France where I had a house, but didn’t live there. Simple system. Cheaper to run than hostile environment. Non-divisive too.
I think I may have mistakenly oversimplified the situation in NL.
But the UK doesn't even know who's here (not even their own citizens), yet through ideology introduce a policy requiring citizens to ask other citizens for "their papers", resulting in widespread discrimination.