As of January 2006, NASK has introduced new telephone numbering based on the pool of numbers it has been assigned as a telecommunications operator that offers voice services.So far, NASK numbers have begun with 5231. Now, the first four digits are replaced with 3808. The remaining three digits in our numbers remain unchanged. For example, the existing reception number 022 523 12 00 has now changed to 022 380 82 00 and the fax number to 022 380 82 01. Please, use the new telephone and fax numbers.