Integrations / Payments, invoicing and accounting

Use AssistCall with Square

AssistCall answers your business calls 24/7 and can send each call, message and booking to Square through Webhook, Live API actions, Zapier, Make, n8n.

Square: Square is Block's payments and point-of-sale platform that small businesses use to take card payments, send invoices and keep a customer directory.

Connects

Example call

A customer calls to ask whether her catering invoice was paid. The receptionist finds her in Square by phone number, checks her invoices, and tells her it's still open with $480 due. The owner gets the call summary by email.

• During a call, the receptionist searches your Square customer directory by the caller's phone number and greets returning customers by name.
• Once it has the caller's Square customer ID, the receptionist searches that customer's invoices at your location and tells them which ones are unpaid and how much is due.
• After a call, a Zap uses Square's Find Customer and Create Customer actions to add new callers to your Square customer directory.

How it connects

• Webhook: Signed JSON for every call, message and booking, sent to any HTTPS URL you choose.
• Live API actions: During the call, the receptionist calls the app's API with your key to look up or create records.
• Zapier: Send AssistCall events to a Zap (Webhooks by Zapier, Catch Hook), then use the app's Zapier actions. Needs a paid Zapier plan.
• Make: Start a Make scenario with a custom webhook and use the app's Make modules.
• n8n: Start an n8n workflow with a webhook node, then call the app with its node or an HTTP request.
• Call forwarding: Forward your business line to AssistCall when busy, after hours or always. Works with any carrier.

About Square's API

• Self-serve API: you can create a key in your account
• Style: REST (JSON)
• Authentication: Personal access token for your own Square account, sent as a Bearer token. It does not expire unless you replace it. OAuth 2.0 is for apps used by other sellers.
• On Zapier: yes. On Make: yes.

A personal access token from the Square Developer Console works in production for your own account. Customer search (POST /v2/customers/search) can match a phone number exactly in E.164 form, such as +12125551234. Square marks the phone filter as beta. Invoice search (POST /v2/invoices/search) needs exactly one location ID, accepts at most one customer ID and can't filter by status, so the receptionist reads each invoice's status from the results. AssistCall's custom JSON body template handles Square's nested search filters. Updating a customer uses PUT, which AssistCall's live API calls don't send, so use Zapier's Square Update Customer action for that. Square webhooks cover customers, invoices and payments.

Not included: no one-click Square app, no listing in Square's marketplace, no two-way sync, and no partnership with Block, Inc..

Researched by the AssistCall team and checked against Block, Inc.'s public pages on October 24, 2026. Square is a trademark of Block, Inc.. AssistCall is an independent product of Starling Global LLC and is not affiliated with, endorsed by, sponsored by or approved by Block, Inc..

More Payments, invoicing and accounting integrations

• PayPal: PayPal is an online payments service that small businesses use to accept payments and send invoices that customers can pay online.
• QuickBooks Online: QuickBooks Online is Intuit's cloud accounting software that small businesses use for invoicing, payments, expenses and bookkeeping.
• Stripe: Stripe is an online payments platform that businesses use to take card payments, bill customers, run subscriptions and send invoices.
• Authorize.net: Authorize.net is Visa's payment gateway that small businesses use, through a merchant account, to accept card and eCheck payments online, in person and over the phone.
• BILL: BILL is accounts payable, accounts receivable and spend management software that small and midsize businesses use to pay bills, send invoices and get paid.
• FreshBooks: FreshBooks is cloud invoicing and accounting software for freelancers and service-based small businesses, with time tracking, estimates and online payments.

All product and company names in this directory are trademarks or registered trademarks of their respective owners, used only to identify systems AssistCall can send call information to or receive information from. Their use does not imply any affiliation with or endorsement by their owners. AssistCall connects using signed webhooks, the business's own API keys, automation platforms (Zapier, Make, n8n) the business sets up in its own account, and call forwarding. AssistCall does not provide one-click connectors, marketplace apps, certifications or two-way record or calendar sync, and does not sign HIPAA business associate agreements. Vendor features, plans and API access can change; information last checked October 24, 2026.