It's the reply from ICA after sending an inquiry to their public contact email.
For your reference.
You may ask the staff to check his/her computer to see whether they have issued you the invitation letter, if yes, then the officer would issue you one immediately. Usually all NUS and NTU foreign students should receive one. However, the change of your mailing address might cause the letter to be mailed to the old address, which is the address in connection with your student visa.
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ICA does send invitation letters for Singapore Permanent Residence (SPR) to final year full time students in our local Institutes of Higher Learning. The SPR invitation letters are merely issued to foreign students to notify them of their eligibility to apply for SPR after their graduation and upon them securing employment here. Recipients of such a letter are not automatically granted SPR. Applications will be subject to consideration.
If you have not received the letter of invitation to apply for Singapore permanent residence, you may call in person with your passport and Student's Pass card at Permanent Resident Services Centre, 5th Storey, ICA Building (Next to Lavender MRT Station), 10 Kallang Road, Singapore 208718 to request for one. Please proceed to the Queue Ticket Counter at the same storey to obtain a queue ticket for submission.
Thank you.
Yours sincerely,