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Bureau of Labor Statistics > Quarterly Census of Employment and Wages > Methods > Additional Resources

Modifying Unemployment Insurance Numbering Systems

An unemployment insurance (UI) number is a unique identifier that multiple data elements rely on. When a state UI office begins a UI modernization project the state may consider creating a new system to assign UI numbers to accounts. It is recommended that the UI numbering system remains unchanged. If the system changes, it is important to implement the changes correctly to avoid the complications outlined in this document.

A state will typically implement UI renumbering in one of two ways:

1. Current accounts keep their UI number, but new accounts will be assigned a UI number based on the new UI numbering system.

2. A new UI number is assigned to all accounts based on the new UI numbering system regardless of account age.

UI renumbering may complicate:

Liability dates and Predecessor/Successor (P/S) relationships
Archived account information
System compatibility
Respondent interaction
Possible impact on other state and Bureau of Labor Statistics (BLS) programs that utilize UI numbers

Liability dates and Predecessor/Successor (P/S) relationships

New UI numbers may create problems with assigning initial liability dates if it becomes difficult to distinguish between a real new account and an account that was assigned a new UI number. Situations like this may contribute to incorrect tax rate assignments based on account age.

It may also become harder to identify a newly assigned UI number from a real P/S transaction. Confusion may arise on which party is liable for paying taxes to UI for a given quarter as a result of predecessor/successor linking complications.

Old UI numbers being reactivated may also create complications if the new system does not identify when inactive UIs are reactivated. The new system may mistakenly reassign a temporarily inactive UI number to a real new account that is not related to the account associated with the inactive UI number.

Archived account information

Some states transfer UI account information to an archive after a specified number of quarters to free up system resources.

Archived UI history will need to be updated or cross-walked if a new UI number system is implemented and the state wants to preserve the accuracy of their historic data. If accounts are not properly linked between the active system and the archive system, complications may arise in:

Tracking payment history
Tax rate changes
Coverage code changes
Determining account age
Transfer of account ownership
Address change information
Creation of duplicate accounts as new UI information is archived

Respondent interaction

There is a dollar cost associated with creating new UI numbers. If all accounts are renumbered, then business owners will need to be notified. This creates an outreach cost due to mailing and a time cost as state staff assist and answer respondent questions about the change. Additionally, a third party may complete documents on behalf of a business. There is no control on how a third party would update or crosswalk UI account numbers maintained in their system. This may create data quality problems as third parties provide the state with incorrect information due to the numbering change.

In addition, it is possible duplicate values may be assigned to multiple unique/unrelated users if the numbering system is poorly designed or implemented. This creates additional respondent burden and may violate confidentiality laws if business data are made available to the wrong business owner.

System compatibility

System compatibility may be an issue if the new UI numbers are more than 10 digits because BLS systems cannot accept more than 10 digits. Using a combination of characters and digits in a UI identifier creates an issue because BLS systems do not accept alphanumeric UI identifiers. If a state's UI number is more than 10 digits and/or alphanumeric, then it will need to be modified prior to being exported and loaded into a BLS system.

Impact on state and BLS programs

It is possible that a UI renumbering project may have an unintentional negative impact on other programs that use state UI data as an input. For this reason it is crucial that all parties in an agency be notified and given time to provide feedback on how a UI renumber may impact their program.

Examples of impact

The LDB assigns a unique number to every account it receives, but that unique number is originally based off of the UI number. If a new UI number is generated for an old account and it is not properly linked, the LDB may count it as a new business (birth) in the system and distort economic growth patterns. Some programs draw their sample from data provided by UI. If UI numbers are not properly cross-walked, it may create issues for programs that use UI numbers to retrieve updated sample information after drawing the original sample.

State UI data are loaded into the ES-202 Database (EDB) after the Enhanced Quarterly Unemployment Insurance (EQUI) file submittal. The EDB uses UI numbers as a way to identify accounts. Multiple quarters of old EDB data may need to be updated if the state UI numbering system changes.

Last Modified Date: September 16, 2019