What Is a CD Number? How to Read a NYC Condo Offering Plan ID
Every condo offering plan filed with the New York State Attorney General gets a plan ID. For condominiums it starts with CD. Here is how to read one and what to do with it.
The Short Answer
A CD number is the plan ID the New York State Attorney General gives a condominium offering plan. It is two letters and six digits, for example CD250420. It's the most reliable way to identify a condo's filing: names change, addresses have several spellings, but the plan ID stays with the filing and every amendment to it.
How to Read a CD Number
Take CD250420, the Morgan Condominium at 38 East 35th Street in Manhattan:
| Part | Value | What it tells you |
|---|---|---|
| CD | Prefix | A condominium plan |
| 25 | Two-digit year | The year the plan came in: 2025 |
| 0420 | Sequence | A four-digit serial number |
The Morgan's ID carries 2025, and the plan was accepted for filing on July 1, 2026. That gap is normal: the Attorney General reviews a plan before accepting it. Across the 8,000-plus accepted plans on Open Book, the year in the plan ID is never later than the year of acceptance, and a little under half were accepted in that same year; the rest were accepted a year or more later.
Older plans work the same way: an ID starting CD06 is from 2006, and one starting CD98 from 1998.
CD vs. CC and Other Prefixes
Of the 8,960 plan records on Open Book, 8,772 start with CD and 188 start with CC. The Attorney General lists most CC plans as combined cooperative/condominium offerings. The prefix is a filing category, so always check the plan type on the record rather than assuming from the letters.
Where to Find a Building's CD Number
- In the Attorney General's database. Search the building's address or name in the Real Estate Finance database; the plan ID is at the top of the record. Step-by-step instructions: how to search the AG's offering plans.
- On Open Book. Search the address and the plan ID is on the result. Every building page shows it, and the buildings directory links every condo offering plan by borough.
- From the new filings list. Recently accepted plans are on the 10 newest NYC condo filings, CD numbers first.
What You Can Do With a CD Number
- Pull up the filing directly. Type it into the AG's database or Open Book's search and you land on one building, with no guessing about spellings.
- Find every amendment. Amendments are filed under the same plan ID. See how to find and read offering plan amendments.
- Tell look-alike buildings apart. Two condos at nearby addresses, or a building that was re-filed after a failed first plan, will have different plan IDs.
- Cite it. In emails to a lawyer, lender or broker, the plan ID removes any doubt about which filing you mean.
The Newest CD Numbers
New plans keep arriving. The 10 newest NYC condo offering plans page lists the latest accepted filings with their CD numbers, addresses, sponsors and unit counts.
Common Questions
Is a CD number the same as a BIN or BBL?
No. A BIN (building identification number) and BBL (borough, block and lot) are New York City identifiers for a building and a tax lot. A CD number identifies an offering plan filed with the New York State Attorney General. One building can have more than one plan over the years.
Does a CD number change when the plan is amended?
No. Amendments are numbered (Amendment 1, 2, 3…) under the same plan ID.
Can I search Open Book by CD number?
Yes. Paste the plan ID into the search box, for example CD250420.
More Guides
- How to Search the NY Attorney General's Condo Offering PlansStep-by-step guide to finding a NYC condo offering plan in the NY Attorney General's Real Estate Finance database: search by address, building name, CD number or sponsor, and open the plan documents.
- What Is a Condo Offering Plan? The NYC "Condo Book" ExplainedA condo offering plan, or condo book, is the disclosure document a NYC sponsor files with the NY Attorney General before selling condo units. What's inside, why it matters, and how to find one.
- How to Find and Read Amendments to a NYC Condo Offering PlanCondo offering plans change through numbered amendments filed with the NY Attorney General. How to find every amendment for a building, what they usually change, and why the latest one matters most.
- Schedule A and Schedule B: Reading Prices, Common Charges and the Budget in a Condo Offering PlanSchedule A lists every condo unit's offering price, size, common interest, common charges and taxes. Schedule B is the first-year budget. How to find both in a NYC offering plan and what to check.
- New NYC Condo Offering Plans: The 10 Latest FilingsThe newest plans accepted for filing by the Attorney General, with CD numbers.