BILL vs Tipalti for Commercial General Contractors

Start by splitting your vendor list into two categories that behave completely differently: subcontractors and suppliers tied to a specific job, and overhead vendors, insurance, equipment leases, office costs, that aren't. Project-tied payables need to carry a job code, a cost code and often a retainage percentage; overhead payables don't. Neither BILL nor Tipalti was purpose-built as construction job-costing software, so this split determines how much custom field mapping you'll need to keep payables tied to the right job in your accounting system.

Many commercial contracts withhold retainage, for example 5 to 10 percent of each subcontractor pay application, until substantial completion, which means every invoice effectively carries two numbers that matter: what's billed and what's actually payable now. BILL and Tipalti both let you short-pay an invoice, but neither natively tracks a running retainage balance per subcontractor across a multi-month project the way construction-specific software does. Plan to keep a retainage ledger in your accounting system or a dedicated job-costing tool, and use whichever AP platform you choose only for the actual payment release.

That division of labor matters more than it sounds: it means your job-costing system stays the source of truth for what's owed on a project, and the AP platform stays the source of truth for what's actually been paid out, two different questions that get confused constantly when a GC tries to force one system to answer both.

Paying a subcontractor before you have a signed conditional or unconditional lien waiver on file is one of the more expensive mistakes a GC can make, since it can leave you exposed to a lien even after payment. Neither BILL nor Tipalti enforces this natively, so the practical fix is a hard rule in your approval workflow: no payment batch releases without waivers and current certificates of insurance attached to the bill record. BILL's approval chains handle this reasonably well since you can require a document attachment before an approver can sign off; Tipalti can do the same but with more setup given its broader configuration surface.

When a sub-subcontractor or major material supplier is at risk of not getting paid by your subcontractor, a joint check, made out to both the sub and the supplier, is standard practice for limiting your own lien exposure. This is a manual workflow in both platforms: you'll issue the check or ACH payment with both payees named and keep the backup documentation outside the automated approval chain, since it's an exception process rather than a routine payment.

If your subcontractor and supplier base is entirely domestic, which is typical for commercial GCs outside of specialty import materials, BILL's faster setup and lower overhead usually wins, and you build retainage and lien waiver tracking as a process around it. Tipalti earns its keep if you're importing specialty materials internationally at real volume, or if you're running payables across multiple entities or joint ventures where Tipalti's multi-entity structure saves real reconciliation time. Payables in engineering and construction run an average of 36 days industry-wide¹, longer than retail or trucking, which is worth knowing when you're negotiating terms with a supplier who's used to a faster-paying customer.

Don't migrate every open job to a new AP platform at once. Pick one active project, run its subcontractor payables through the new system for a full pay-application cycle, and confirm retainage tracking, waiver attachment and payment timing all work the way your team expects before adding the rest of your job list. A GC running a dozen jobs at once can't afford a broken payment run on all of them simultaneously; a single-job pilot limits the blast radius if something in the workflow doesn't translate the way the vendor's demo suggested it would.

What to confirm during the pilot job:

• Retainage holdbacks are short-paid correctly on each subcontractor pay application.
• Signed lien waivers are attached before an approver can release any payment.
• Payment timing matches what your team expects across a full pay-application cycle.
• Job codes and cost codes carry through on every project-tied payable, separate from overhead.