ACT 15 & 16 AND FINAL PAYMENT
These are granted by the local council for the municipality in which your apartment complex resides.
Act 15 - Upon completion of the construction works, the building has to be accepted by an especially appointed technical commission. If all construction works comply with the technical requirements, this commission issues Act 15 certifying the building.
Act 16 - Having issued Act 15, the development has also to pass through all inspection commissions connected with the communications (water supply, electricity, etc.). After having checked and approved all installations, it issues Act 16 - Permission for Use.
(NB This does not mean that the complex is ready for use as a rental proposition e.g. swimming pool filled up, gardens landscaped etc.)
You should not be requested to make the final payment until Act 16 has been granted, although in practice this may not be the case.
At this point, you may also be expected to pay any property taxes due and also the annual maintenance charge for the common parts.
You then have up to three months to formally complete on your Bulgarian property.