Blue card or single permit ?

hello,

blue card is used often in other EU Schengen state, but not in Belgium...
Blue card forces you to receive a higher salary than the single permit as it seems you've understood, so.... everybody do the single permit... as it's easier for the companies and basically everybody.
At some point, Blue card is a european visa/law, while the single permit is a national visa. What I'm saying here is not 100% true, I over simplify just to make your understand the big differences. You'll find all the info in europa.eu


Blue card has the advantage to switch work in another EU states pretty easily, while under single permit regime you'll have to wait 5 years of work to get the D card to have +/- the exact same advantages to move with way less administrative stuff (or to apply for a new worker visa request to go abroad (but if you're already working in EU, it's easier... even if you're not yet a permanent resident (D Card)))


Both resident permit (under blue & single permit regime) will allow you to invite your family as you'll have enough finance per month to do it correctly + you'll be a RESIDENT in Belgian.
As you want to invite your mum for tourist/family visit purpose, as far as I get it, you've to understand that it's HER financial situation that matter ==> SHE can cover for her trip, NOT you. (read between the line, if she doesn't have enough money in a Belgian point of view, send her money on her bank account, then tell her to give the 3 last bank statement without your payment in it!)
Of course, the administation will be please to see that she can show an annexe 3bis (that proof you've the finance to take care of her, that you pay for the flight ticket etc... but she still MUST proof she has the bare minimum to take care of herself if you throw her away and finally decide to not take care of her)


For your information: https://sif-gid.ibz.be/FR/montant_belgique.aspx she must proof that she has AT LEAST:
45€ per DAY of stay if you give an invitation letter (+ signature legalized at the commune: 1€)
95€ per DAY if she plans to stay in Hotels during her stay.
And of course, make sure she's not border line and make sure she can show a "bit" more money!

so if you invite her for 21 days in Belgium, she must at least show: 30 * 45 = 1350€ (tip/in fact make it 2000€) + other proof she'll get back in her country (husband, accommodation, family, ... don't just state it, PROVE it! resident certificate of the husband, sister/brother that live in the same street, whatever ==> she'll get back home because she has everything in her home country)

For a Schengen visa you must proof:
* the reason of your trip (family visit)
* how everything is paid (she has the bare minimum money on her OWN + you cover)
* reason why she'll get back home no matter what (accommodation, car, boat, family, job...)