Client: BES Bookkeeping
Industry: Construction / Accounting Services
Location: New Jersey, United States
Challenge: Processing approximately 100 tax exemption certificates with multiple data fields across several tax years
Executive Summary
BES Bookkeeping, a New Jersey-based accounting firm, needed to process hundreds of ST-8 Certificate of Exempt Capital Improvement forms across multiple years (2023-2025). The manual process of filling individual PDFs was time-consuming and error-prone. By implementing Instafill.ai’s batch processing solution, the firm successfully automated their form-filling workflow, reducing processing time from hours to minutes while ensuring accuracy and compliance with New Jersey tax requirements.
The Challenge
Form ST-8 must be completed for every qualifying construction project. It allows property owners to certify that work qualifies as an exempt capital improvement, so contractors do not collect sales tax on labor charges. Contractors must retain a completed certificate for each exempt project.
For one construction contractor client, BES Bookkeeping faced filling out hundreds of these forms across multiple years:
- 2025 data: Estimated less than 100 forms
- 2024 data: Full year of projects to process retroactively
- 2023 data: Additional year requiring documentation
Manual processing would require opening each form individually, typing in the customer information, saving the file, and moving to the next. With potentially hundreds of forms to complete, this represented days of repetitive data entry work.
The Batch Processing Requirement
The critical requirement was batch filling capability. Rather than filling forms one at a time, BES Bookkeeping needed to:
- Upload a single Excel spreadsheet containing all customer data
- Generate all completed PDFs in one operation
- Download the filled forms for contractor records
The firm already had customer data organized in Excel with the four required columns. They needed a system that could map spreadsheet data to form fields and produce hundreds of completed PDFs without manual intervention.
The Solution
Brooke used Instafill.ai to automate the process. She uploaded the ST-8 form and her Excel spreadsheet. The Instafill.ai team worked closely with Brooke in her ST-8 form setup. Key steps included:
- Field Mapping and Gaps: Instafill identified the missing owner-address field and added it to the form so that the “Address of owner of real property” now appears and populates correctly in both sections. All field names and descriptions were adjusted so the AI can match them to Brooke’s spreadsheet.
- Text Alignment: Brooke’s contracts often had very long descriptions. During review, Instafill noted that a lengthy “Nature of contract” text could overflow one line. To handle this, a second form variant (ST-8 v2) was created with a larger text area. This ensures longer contract descriptions fit without truncation.
- Currency Formatting: The team also corrected the handling of numeric fields. (Brooke’s Excel had commas in the “Total amount” column, and Instafill was initially stripping them.) This was fixed so that commas in currency values are preserved in the output PDFs, ensuring legally correct formatting.
Updates were made overnight, with Brooke testing and providing feedback on field placements and unnecessary fields. The final form versions worked for her batch processing needs.
The Result: Multi-Year Processing Capacity
Instafill.ai allowed BES Bookkeeping to generate completed ST-8 forms from the Excel data without manual entry for each one. Previews and downloads showed all data correctly, with no formatting issues. This handled the multi-year project, starting with 2025 and continuing to prior years.
Brooke noted in support chat: “thank you for all your help! this software is great just trying to learn everything!”
BES Bookkeeping could now manage these forms for construction clients more efficiently.
Performance Metrics
Processing capability: 100+ forms per batch operation
Time savings: Minutes instead of days for multi-year data processing
Data source: Direct Excel upload with four-column structure
Delivery: Batch-generated PDFs downloadable as individual files or ZIP archive
Why Batch Processing Matters for Construction Bookkeeping
Bookkeeping firms serving construction contractors face unique documentation burdens. Construction tax compliance requires maintaining detailed records for every project, and forms like ST-8 must be completed accurately to support sales tax exemptions.
The ST-8 Compliance Requirement
New Jersey requires contractors to retain completed Form ST-8 certificates for all exempt capital improvement projects. Without a properly completed certificate, contractors must collect sales tax on labor charges – even for work that qualifies for exemption.
For a busy construction contractor, this means:
- Multiple ST-8 forms per month during peak season
- Historical documentation needed for tax audits
- Accuracy critical to support exemption claims
- Proper retention required (minimum 4 years per NJ regulations)
Manual processing creates two problems:
- Volume bottleneck: Bookkeepers spend hours on repetitive data entry
- Error risk: Manual typing introduces transcription mistakes
Batch processing addresses both issues by automating the data transfer from spreadsheet to form.
Construction-Specific Form Requirements
Form ST-8 is standardized, requiring the same fields across projects:
- Contractor and property owner info
- Contract description and amount
- Physical address for work performed
The consistent form structure with varying data makes it ideal for batch automation, increasing processing speed and accuracy.