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Paper Boundary and Annexation Survey (BAS) FAQ and Tips

Can I just send in a map of the entire boundary?

We cannot accept or process submissions that only show the entirety of your boundary. Individually drawn changes allow us to process changes to our database in a uniform manner, while also providing us with all of the required information needed for legal changes and boundary corrections.

How do I make changes on the maps?

Colored pencils are included in the original mailing package. We ask that you use the red pencil to update any changes to the boundary of your entity and the purple pencil to make any changes to the road networks, address ranges, or areal features (parks, airports, etc.) within your entity. Note that changes made in lead pencil or pen are sometimes more difficult to recognize due to existing symbology color.

Do I treat old legal boundary changes that were never previously reported to BAS as annexations/deannexations or boundary corrections?

If a legal boundary change appears to have never been reported (regardless of effective date), report it as an annexation/deannexation. If the change is just a correction to the way we have the boundary currently depicted (these should maintain the general shape of the boundary), report it as a boundary correction. If you are not sure, treat it as an annexation/deannexation and provide the documentation number and effective date.

How do I return my maps to the Census Bureau?

You have a choice of returning your maps via US Postal Service with the Business Reply Label or via FedEx with the Pre-Paid Return Label included in your original mailing. Please only return maps that have changes on them.

What is my 11-digit BAS ID?

BAS IDs can be found on our BAS Codes page.

What is Consolidated BAS (CBAS)?

To reduce the burden on local governments and avoid duplication of efforts, the Census Bureau offers consolidation agreements to counties that are interested in submitting boundary changes for the legal governments (incorporated places and minor civil divisions) within their jurisdiction. The Consolidated BAS (CBAS) program allows counties to report boundary and feature changes for some or all of the legal governments within their county. Once a local government agrees to the consolidation, the local government will no longer receive BAS materials. Instead, the county BAS respondent will be responsible for providing the Census Bureau with all boundary updates.

For more information, visit the CBAS page.

I am a county respondent, what changes am I responsible for submitting?

As a county respondent, we are asking you to review and update your county boundaries as needed. However, most county respondents also report changes for the legal governments (incorporated places and minor civil divisions) within their jurisdiction. Some counties have entered into a Consolidated BAS (CBAS) agreement with those governments, which states that the county will be responsible for reporting changes for all (or a portion of) governments within the county, reducing duplication of effort.

For more information on the CBAS program, please visit the CBAS page.

I have a legal change that is effective after January 1st. Should I go ahead and include that in my changes, or wait until next year’s BAS?

Go ahead and include all of your legal changes. We will process them accordingly per the effective date in the attribute table. Legal changes that are effective after January 1st will not be processed for inclusion in the current year’s Census programs (such as the Population Estimates Program and American Community Survey). They will be processed at a later time in order to be included in the following year’s BAS products.

When will my changes be reflected?

This depends on the type of changes you submit, when you submit them, and (for boundary corrections) the number of changes in your submission. Any legal boundary changes which are received by the deadline of March 1st and were effective by January 1st of the same year will be reflected in the products from the same year's ACS (generally this data is available in July of the same year). All legal boundary changes received after March 1st but before May 31st will be reflected in the next year’s BAS products. Boundary corrections and feature changes will generally all be reflected in the next year’s BAS products, but if you submit a very large file with many boundary corrections or features changes, we cannot guarantee that all of them will be reflected. In that case, any remaining boundary corrections and feature changes will be processed as time and resources permit.

Source: U.S. Census Bureau | Geography | (301) 763-1128 |  Last Revised: October 28, 2013