Candidates must have advanced Excel skills, including experience with Pivot Tables, SUMIFS, VLOOKUP/XLOOKUP, and formula‑driven spreadsheets, and typically possess 3–10 years of experience in billing, accounts payable, accounting, bookkeeping, or large‑scale enterprise billing. Billing Specialist I: Demonstrates the ability to complete basic billing data entry, completes non-complex report formatting, shows an understanding of the operations that occur in Casella Resource Solutions, creates invoices, and resolves any billing-related issues.