BILL vs Tipalti for Commercial Solar and Energy EPC Firms

Most services businesses have a fairly steady payables rhythm: recurring overhead, a handful of vendors, predictable timing. An EPC contractor's payables instead move in bursts tied to a project's construction schedule, a heavy equipment payment at kickoff, a quiet stretch during permitting delays, a wave of subcontractor payments once construction actually starts. Whichever platform you choose needs to handle that unevenness without either bottlenecking during a payment-heavy week or sitting idle during a quiet one.

Panels and inverters are frequently sourced from manufacturers outside the US, even when a US distributor is the nameplate seller, and larger EPCs sometimes buy directly from an overseas manufacturer to hit project margins. If your equipment purchasing runs through a domestic distributor, BILL covers it without added complexity. If you're negotiating directly with international panel or inverter manufacturers, Tipalti's multi-currency payment handling and tax documentation collection remove a meaningful amount of manual work compared to routing those payments as one-off international wires.

Racking installation and electrical subcontractors on a project like this are usually paid in stages tied to physical progress, mechanical completion, electrical rough-in, final commissioning, rather than a single invoice at the end. Neither BILL nor Tipalti tracks project milestones natively, so the schedule of what's due at each stage needs to live in your project management system, with the AP platform handling the actual payment release once a stage is confirmed complete and approved.

Permitting fees, interconnection application fees and utility charges are typically small relative to equipment and labor costs, but they're often tied to hard deadlines: miss a permitting fee payment and the project's interconnection timeline slips, which can cascade into missed incentive deadlines depending on the program. These are exactly the kind of low-dollar, high-urgency payments worth routing through a fast-track approval tier in either platform, similar to how a field service business handles emergency parts purchases.

By the time that project reaches interconnection, the payables trail typically includes one or two large equipment purchases, several milestone-based subcontractor payments, and a handful of small permitting and utility fees, three very different payment shapes on one job. The general operations manager or project lead overseeing payables on a project like this typically earns in the $72,320 to $167,280 range depending on seniority and company size¹, which is worth knowing when deciding how much of this coordination you can reasonably expect one person to own versus when it's time to split project financial administration across two roles.

A contractor running mostly domestic-sourced equipment and a stable subcontractor bench fits BILL's setup well. A contractor negotiating directly with international manufacturers on larger projects, or running payables across multiple project entities for financing or tax reasons, gets more value from Tipalti's broader configuration despite the heavier setup.

A single project's payables are manageable in almost any system; the real test is a dozen projects at different stages simultaneously, one at permitting, several mid-construction, a couple at final commissioning, each generating its own mix of equipment, milestone and fee payments on its own timeline. At that point, whichever platform you use needs project-level tagging on every payable so a project manager can see their own job's payment status without digging through the whole company's AP queue, a need that grows faster than most contractors expect once the backlog fills up.

A fast-track approval tier for permitting and utility fees is only safe if it's bounded clearly: a set dollar ceiling, a defined list of fee types that qualify, and a monthly report of everything that went through the fast path so someone is still reviewing the pattern even though individual payments cleared quickly. Skipping that oversight step is how a fast-track exception meant for a small permitting fee quietly starts covering larger payments nobody meant to fast-track, and by the time anyone notices, the exception has effectively become the rule.

Guardrails for a fee fast-track tier:

• Set a fixed dollar ceiling so only small permitting and utility fees can use the fast path.
• Define the list of fee types that qualify, such as permitting and interconnection application fees.
• Review a monthly report of everything that went through the fast path so someone still sees the pattern.
• Keep equipment invoices on the fuller review that a larger purchase deserves.