Best Collections Software for Professional Services Firms in 2026

Disclosure: Abivo is our product. Facts about other tools come from their own websites as of October 2026.

The short answer: Consulting, engineering, architecture and IT services firms bill in ways that make collections awkward: monthly time and materials, fixed-fee milestones that need client sign-off, retainers that need topping up, and invoices that sit with a project sponsor who never forwards them to AP. PSA tools like Kantata and BigTime are strong at turning approved time into accurate invoices, and BigTime includes built-in invoice reminders. For the follow-up itself, Abivo's AI agent calls, texts and emails clients about overdue invoices in your firm's name and hands scope disputes to your team with the full history. Upflow, Growfin and Chaser suit finance teams that want a dedicated AR platform they configure and staff themselves.

Comparison table

Abivo

Abivo is AI collections software for B2B finance teams. Its AI agent, Kate, calls, texts and emails clients about overdue invoices in your firm's name. Kate records promises to pay, disputes and next steps, and hands disputes and requests to speak with a person to your AR team with the full history.

That handoff matters in professional services, where "we're still reviewing the deliverable" is a common reason for nonpayment. A scope or deliverable dispute should reach the project lead, not get another reminder. You can flag key accounts so a named owner, such as the engagement partner, handles them, and you can pause any single invoice while a milestone sign-off is pending. Reminders name the invoice details your client's AP team needs, such as the project, PO and billing period, and one message can cover every open invoice on an account.

You set the cadence per account or segment, so a long-standing enterprise client can get a gentler rhythm than a new small client. Multi-entity firms keep each subsidiary separate, and Abivo works with clients in over 50 countries and in any currency. It connects with QuickBooks, Xero, NetSuite, Sage Intacct, Microsoft Dynamics 365 Business Central, SAP and Chargebee, or an aging report export. Abivo does not replace your accounting system, invoicing, payment processing or cash application, so your PSA keeps producing the invoices.

As proof of the agent in a B2B setting, "OFS Group, a fire protection contractor, collected $842,518 in its first four months with Abivo" (case study). For industry detail, see our guides for consulting firms, engineering firms and architecture firms.

Choose it when: partners, PMs or a single bookkeeper are chasing overdue invoices between billable work, and you want consistent phone, text and email follow-up without changing your PSA or accounting system.

Kantata

Kantata positions itself as PSA software for professional services firms and agencies, with industry pages for consulting, IT services, software and agencies. Its invoicing page says you can "invoice clients directly on work performed and expenses incurred," with approval workflows for time and expenses, PO tracking to reduce disputes, batch invoicing, alerts when items are ready to bill, per-client invoice templates, and support for multiple languages and local tax rules. It works with QuickBooks, Xero, NetSuite and Sage. Its financial management page refers to "proactive communication and collections" as a way to reduce DSO. The invoicing page does not describe automated payment reminders.

Choose it when: your biggest AR problem starts upstream, with late or inaccurate invoices, and you want resource planning, project accounting and billing in one system.

BigTime

BigTime describes "invoicing that's tied directly to project financials, not just line items," with client, role and project billing rates and approvals before billing. It names accounting, architecture, consulting, engineering and IT services as target industries and offers bi-directional sync with QuickBooks Online and Desktop. Its invoice management page mentions online payments, "automatic payment reminders" and visibility into outstanding and overdue invoices, plus deposit requests and recurring billing.

Choose it when: you are a small or midsize firm on QuickBooks that wants time tracking, project billing and built-in invoice reminders in one tool.

Upflow

Upflow describes itself as "the platform B2B finance teams need to collect smarter." It offers multi-step dunning sequences, "Smart Rules" that route clients by segment, outreach by email, phone calls, SMS and postal letters, a branded payment portal with a promise-to-pay option, and integrations with NetSuite, Sage Intacct, QuickBooks Online, Xero, Salesforce and HubSpot. See our Upflow alternative comparison.

Choose it when: you have an in-house AR team that wants to build its own sequences and portal experience and staff the calls itself.

Growfin

Growfin says its "AI agents analyze, prioritize, and execute across your AR lifecycle." Its collections page describes a health score built from live factors such as broken promises to pay, configurable workflows, an AI-led AR inbox that summarizes threads and drafts replies, cash forecasting, and a customer portal where clients can raise disputes and log promises to pay. It lists a NetSuite SuiteApp and Salesforce, HubSpot and Slack integrations. The page describes email-led follow-up and does not describe phone or SMS outreach.

Choose it when: you are a larger firm with collectors who work mostly by email and want AI help prioritizing accounts and drafting replies.

Chaser

Chaser markets credit management software for business service providers. Its business services page says clients can be segmented so hourly, project-based and retainer billing each follow their own reminder schedule, with reminders by email, SMS, letter and automated phone call, a customer billing portal, and integrations with QuickBooks, Xero, Sage, Business Central and SAP. Chaser also offers outsourced credit control specialists. See our Chaser alternative page.

Choose it when: you are a smaller firm that wants templated reminders by billing type and likes having outsourced credit control as an option.

How to choose collections software for a professional services firm

Professional services AR fails in specific places. Test each tool against these.

• Milestone and fixed-fee invoices: Fixed-fee invoices often wait on a client signing off a deliverable. You need a way to pause one invoice while sign-off is pending, then resume follow-up the day it is approved.

• Retainers and deposits: Retainer top-ups and deposit invoices are easy to ignore because work is already underway. Give them a firmer cadence before the retainer runs dry.

• The sponsor versus AP problem: The person who hired you is rarely the person who pays. Make sure the tool can reach the AP contact and include the project name, PO and billing period so AP can match it.

• Scope disputes: "That wasn't in the SOW" should go to the project lead with the conversation history, not trigger another reminder. Check how each tool routes disputes.

• Partner relationships: Some clients belong to a partner. Flag those as key accounts so a named owner handles them, while automated follow-up covers everyone else.

• Consolidated statements: Clients with several active projects should get one message covering every open invoice, not one reminder per project.

• International clients: Engineering and IT services firms often bill in several currencies. Confirm the tool handles your client countries and currencies.

• PSA and ledger fit: Kantata, BigTime and similar PSAs usually push invoices into QuickBooks, Xero, NetSuite or Sage Intacct. Confirm the collections tool reads from that ledger.

• Who makes the calls: Many firms find clients respond to a phone call when emails stall. Decide whether the software makes calls for you, as with AI collections calls, or gives your staff a call list.

For process advice beyond software, read our guide to professional services AR and getting clients to pay on time.

To see how Abivo would handle your own client list, book a 30-minute demo on your own aging report.

Frequently Asked Questions

What is the best collections software for a consulting firm?

If your PSA already produces accurate invoices but nobody follows up consistently, an AI collections agent like Abivo adds calls, texts and emails in your firm's name and routes scope disputes to your team. If you want reminders inside your PSA, BigTime includes built-in invoice reminders. Larger finance teams that want to configure their own sequences often look at Upflow or Growfin.

Does Kantata or BigTime handle collections?

Kantata focuses on producing accurate invoices from approved time and expenses and gives AR visibility, but its invoicing page does not describe automated payment reminders. BigTime's invoice management page mentions online payments and automatic payment reminders. Neither describes phone follow-up on overdue invoices.

How do engineering and architecture firms get clients to pay milestone invoices faster?

Send the invoice the day the milestone is approved, include the project, phase and PO, and follow up on a fixed cadence. Pause the invoice if the client disputes the deliverable and route it to the project lead, then resume follow-up once the issue is resolved.

Can collections software work with my PSA tool?

Usually through your accounting system. Abivo connects with QuickBooks, Xero, NetSuite, Sage Intacct, Business Central, SAP and Chargebee, or an aging report export, so it works with whichever PSA feeds that ledger.

Will automated collections calls annoy my clients?

You control the timing. With Abivo you set the cadence per account or segment, pause any invoice, and flag partner-owned clients so a named person handles them. Any request to speak with a person goes to your team with the full history.