Russia Postal Code Format Explained

A Russian postal code, called the postal index (почтовый индекс), is a six-digit number written without spaces, hyphens or letters. It is assigned by the national postal operator and identifies the post office that serves an address, not an individual building.

Structure of the six-digit index

The index is purely numeric. Its first three digits generally relate to the region and the main sorting or processing centre, and the last three digits point to the specific post office or delivery unit within that area. You do not need to calculate or interpret the parts yourself; the whole six-digit number should always be written and entered together.

Some practical consequences follow from this design:

• Several streets, or a whole small town or village, may share a single index.
• A very large city has many indexes, one per delivery unit, so the index changes between districts.
• Two addresses on the same street can occasionally carry different indexes if they are served by different offices.

Examples of valid format

These values only demonstrate the format and are not real indexes:

• 123456 — six digits, no separator
• 654321 — another six-digit value; the first digits vary by region

A string such as 12 34 56, 1234, 12345-6 or RU-123456 is not a valid index as written.

How it appears in an address

In Russian addresses the index traditionally comes first, before the country and region, and on paper envelopes it is often written in a dedicated row of boxes. In online forms it is a separate field. The full structure is covered on the address format page.

Common mistakes

• Dropping a digit or adding a space. Forms that validate the field usually require exactly six digits.
• Using the index of a neighbouring office. Copying the index of a nearby town because it looks close can send a parcel to the wrong post office.
• Confusing the index with a phone or area code. They are unrelated numbers.
• Treating the index as a precise location. It narrows delivery to an office area, so the street, house and flat still need to be written out.
• Substituting a UPCS code for the index. A UPCS code such as RU-XXXX-XXXX is not an official postal index and cannot be entered in an index field.

If you are unsure which index applies to an address, follow the steps on how to find a postal code in Russia.

Where UPCS fits

The official index gets a parcel to the right post office region. A UPCS code, which points to a 3 m by 3 m cell, can be added in a comment or note field to mark the exact entrance. See the Russia overview for how the two work together.