Customer Billing & AR Specialist

About lemlist

lemlist is the outbound platform for sales teams: find leads, run multichannel campaigns (email, LinkedIn, calls), personalize with AI and book meetings.

lempire also builds lemwarm (deliverability), Claap (AI call intelligence), Taplio and Tweet Hunter.

We're at +$60M ARR, growing ~50% year over year, profitable and 100% bootstrapped, with 180 people.

We’re now moving upmarket, signing larger deals, expanding our partnerships, working with data providers, and integrating acquisitions like Claap.

Thousands of customers pay us every month, from self-serve sign-ups to multi-year sales contracts, and we need you.

Your mission

Every deal we close and every plan a customer changes goes through billing. When a quote is set up wrong, the customer gets the wrong invoice, Sales and Customer Success lose time, and cash comes in late.

As our Customer Billing & AR Specialist, you'll make sure every quote is right, every invoice matches what we sold, customers get fast and clear answers, and they pay on time. You'll also be the billing partner of our Sales team: the person reps turn to when a deal doesn't fit the standard path.

You'll join the Operations team. You'll work hand in hand with Luka, who runs customer billing and accounts receivable today, and with Mathilde, Senior Ops Manager, and the rest of the Operations team, who design our quote-to-cash processes. You bring what you see in the daily run, and together you make the process as efficient as possible. You'll also work daily with Sales, Key Account Managers, Customer Success, Support, Finance and Product.

Your focus is quote correctness and support to Sales, invoices in Stripe for lemlist and Claap, billing communication with customers, collections for your customer portfolio, and making that run lighter month after month.

What you will do

Get every quote right and help Sales navigate billing

• Own quote correctness: review quotes before they go to the customer and before they reach billing (plan, price, discounts, payment terms, billing entity), using our quote checker and CRM rules.

• Be the go-to billing person for Sales and Key Account Managers: help them structure deals, pick the right plan and terms, and use our quoting tools.

• Steer reps in the right direction when a deal doesn't fit our rules, and help them find a setup that works for the customer and for us.

• Reply fast to Sales requests, especially when a deal is about to close. No rep should lose a deal waiting for billing.

• Explain billing rules in plain words, and walk new reps through them.

Master Stripe and keep every invoice right

• Become our Stripe expert: subscriptions, invoices, credit notes, refunds, coupons and taxes.

• Set up subscriptions from signed deals: new plans, upgrades, downgrades, add-ons, seat changes, discounts and multi-year contracts.

• Check that invoices & subscriptions are correct, edit them when needed, and issue credit notes and refunds when they apply. Make sure product access matches what the customer pays for and automated tax collection was correct.

• Take over billing for Claap and help align its Stripe setup (products, prices, coupons, metadata) with lemlist's.

• Back up Luka on billing requests and collections, and he backs you up, so the run never depends on one person.

Own billing communication

• Answer billing questions from customers, Customer Success and Support, within agreed response times.

• Work mainly on our afternoon-to-evening shift, ending at 21:00 or 22:00 Belgrade time, so customers and teams in the US get answers the same day. You start on standard hours during onboarding, and hand over with Luka every day.

• Turn recurring questions into clear answers: FAQ, macros, internal guides. The same question should not come back every week.

• Fill in the supplier forms customers send us, with accurate company, tax and bank details.

Collect payments on time

• Own collections for a portfolio of customers, starting with accounts in American time zones: failed payments, reminders, overdue invoices.

• Work with customers and account owners to unblock payments: card updates, purchase orders, bank transfers, payment terms.

• Register us on customers' supplier portals (Coupa, Ariba or similar) and handle supplier eligibility checks, with the company, tax and bank documents they need, so our invoices get received and paid.

• Keep our dunning sequences in Stripe and our AR tool up to date, and follow each overdue invoice until it is paid, credited or escalated.

• Report overdue amounts and risks on your portfolio every week, and agree with Luka when to suspend access or escalate.

Keep billing clean and compliant

• Keep Stripe and HubSpot consistent (customer data, products, metadata) so revenue reporting stays reliable.

• Apply our compliance rules in the daily run: sanctioned-country blocks, payment fraud signals, VAT and sales tax data on customer accounts.

• Flag anomalies early: failed payments, unusual refunds, accounts without an owner.

Make the run lighter

• Document every process you touch in Notion.

• Work with the Operations team to improve our quote-to-cash processes: share what breaks in the daily run, test new processes early and quickly to give feedback, become the first point of contact when a new process or tool is rolled out.

• Track recurring billing issues and bring them to the Operations team with volume and impact, so root causes get fixed in the process or the product.

What success looks like

Within your first 3 months

• You know our plans and billing flows for lemlist and Claap, and handle Stripe on your own: subscriptions, invoice edits, credit notes, refunds.

• Sales reps come to you first with billing questions and get answers within agreed times.

• You share billing requests with Luka, with agreed response times and no backlog.

• You've documented the main billing processes and published a first billing FAQ for Sales, KAM and Customer Success.

• You've mapped the top recurring billing issues and their volume.

• You own collections for your customer portfolio, with a weekly overdue report.

Within 12 months

• Claap billing runs on the same setup and rules as lemlist.

• Quote errors rarely reach billing, and fewer invoices need to be edited or recreated.

• Recurring billing questions from internal teams have dropped against your 3-month baseline.

• Overdue amounts on your portfolio are down against your 3-month baseline.

• You've contributed to at least two process improvements with the Operations team or Product.

Who you are

Must have

• 1 to 4 years of experience in billing operations, accounts receivable, order-to-cash or finance operations, ideally in B2B SaaS.

• Hands-on experience with a subscription billing system (Stripe, Chargebee or similar): plans, prorations, discounts, invoices, credit notes, refunds, multiple currencies.

• Rigor. You check the details, and your setups are right the first time.

• Clear written communication with customers and internal teams, including when the answer is no.

• Comfortable steering salespeople. You can tell a rep a deal setup won't work, and help them find one that does.

• Firm and friendly when chasing payments. You can get a customer to pay without damaging the relationship.

• Comfort with numbers and spreadsheets. You can reconcile a list of invoices and spot what doesn't match.

• Reactive, with a service mindset. You answer fast and follow a request until it's closed.

• Comfortable asking questions when you don't know. You'd rather check than guess.

• At ease with change. Our rules and tools evolve fast, and you adapt quickly.

• Fluent English.

• Based in Serbia, and comfortable working an afternoon-to-evening shift, until 21:00 or 22:00 local time.

Nice to have

• Deep Stripe Billing experience, plus HubSpot and an AR / dunning tool (Upflow or similar).

• Basics of e-invoicing & Indirect sales tax for SaaS (VAT, US Sales tax).

• A general understanding of tech tools: you pick up new SaaS tools quickly and see how they connect.

• A good command of French is a plus

What is in it for you

• A central role in a profitable, growing SaaS group. You'll see how Sales, Product and Finance connect.

• Real ownership of your scope, with teammates who know billing inside out.

• Room to improve processes with the Operations team, with the tools you need.

• Remote, async culture with flexible hours, in an international team.

Recruitment process

1. Interview with Victoire (Lead TA)

2. Interview Phil (Head of Finance & Ops)

3. Practical case and live debrief with Mathilde (Senior RevOps) and Luka (Billing specialist)

4. Quick chat with Oriane (COO)

5. Reference checks and offer.