For the Netherlands
A purchase with Pay in 3 is not registered with the Bureau Krediet Registratie (BKR).
This is because you repay the amount in three instalments within 90 days. Credit agreements with such a short duration are not registered with the BKR.
It is important that you pay your instalments on time.
If you do not pay (on time), this may lead to consequences such as additional costs or further debt collection measures.
If you always pay on time, Pay in 3 will not affect any BKR registration.
Helpful links:
How are my payments processed?
What happens if I do not pay my payments (on time)?