Tricky situation: Birth certificates from different countries

[leonht]

For example, I'm a citizen of Spain, but I was born in Portugal and I have birth certificates (BC) from both countries.
However, my first names are different on Portuguese and Spanish BC, because my parents changed my name after they applied for Portuguese BC and before getting Spanish BC.
I've always used the name on my Spanish BC everywhere (passport, school records, study/work permits, T4, etc.). In fact, I almost forgot that the Portuguese BC exists...

In this case, should I declare that I've used other names and attach a letter of explanation saying that the name exists only on my birth certificate and isn't used anywhere else?

 

[SAJ_ee2015]

For example, I'm a citizen of Spain, but I was born in Portugal and I have birth certificates (BC) from both countries.
However, my first names are different on Portuguese and Spanish BC, because my parents changed my name after they applied for Portuguese BC and before getting Spanish BC.
I've always used the name on my Spanish BC everywhere (passport, school records, study/work permits, T4, etc.). In fact, I almost forgot that the Portuguese BC exists...

In this case, should I declare that I've used other names and attach a letter of explanation saying that the name exists only on my birth certificate and isn't used anywhere else?

Just for your information: If you are a single applicant, You dont need need to submit birth certificate. Its purpose is to prove relationship with dependent children.
http://www.cic.gc.ca/english/resources/tools/perm/express/intake-complete.asp

(I dont know your case, just thought of sharing this information )

 

[bellaluna]

Submit the BC that matches your passport name and list the other name as an alias in the application form when it comes up. The explanation will help.