Accounting Services in Darien, IL

CPA Services for Darien Households and Local Businesses

What Darien’s commercial areas look like

Choose DuPage describes Darien as a mostly residential community of about 21,855 people, with commercial and office areas set among the neighborhoods. It names the I-55 (Stevenson Expressway) frontage, 75th Street, Lemont Road and Cass Avenue as the growth corridors. Darien is about 17 miles from Chicago’s Loop. Choose DuPage puts total employment at 12,042 and the daytime population at 18,815, lower than the number of residents. If you own a business along one of these roads, you may also live in town, so your business and personal returns tend to be planned together.

Sales tax in 2026: 8.00% to 8.50%

Darien’s rate changed twice this year, according to Illinois Department of Revenue rate files. It rose from 8.00% to 8.25% on January 1, 2026, and then to 8.50% on August 1, 2026. Retailers and restaurants should confirm their registers picked up both changes.

Where we fit in

For a Darien owner who does their own books until tax season, the work usually splits three ways:

• Small business accounting and tax: monthly or quarterly financials plus the annual return, handled together.
• Payroll: pay runs, Illinois withholding and the quarterly and annual payroll filings for a small staff.
• Tax preparation: the federal and Illinois returns, including the 4.95% individual return for owners whose business income passes through.

If the business is an S corporation or partnership, the entity also owes Illinois Personal Property Replacement Income Tax of 1.5% of net income, which is a separate line from the owner’s personal tax.

On the property side, DuPage County reviews every property assessment in its general assessment years, which come every four years. The most recent was 2023, so 2027 is the next one. Business owners who own their building may want to plan for that year’s change of assessment notices.

From Darien to Butterfield Road

Our office at 1323 Butterfield Rd, Downers Grove is about 10.6 miles by road from Darien. Call (331) 264-4194 or send a note through the contact page.