# Associate Invoice Reconciliations (Media) at Critical Mass

> Costa Rica · Junior · Other · open. Source: https://alderhq.app/jobs/greenhouse%3Acriticalmass%3A8114082 (read 2026-11-08).

## Facts (observed)

- Company: [Critical Mass](https://alderhq.app/companies/critical-mass)
- Location text: San Jose, Costa Rica; San Jose
- Where it can be done from (inferred): Costa Rica (evidence: "Location: San Jose, Costa Rica; San Jose")
- Posted: 2026-09-23 (46 days ago)
- First seen by alder: 2026-11-04 · last verified: 2026-11-08
- Reposted: 0 times · edited: 0 times
- Apply on the employer's site: https://job-boards.greenhouse.io/criticalmass/jobs/8114082

## Pay and sponsorship

- Posted pay: not posted
- Market band for similar posted roles (SF Bay Area, n 262): p25 $70k, median $98k, p75 $124k

## Description (the employer's text)

Join Critical Mass as our Associate Invoice Reconciliations (Media) with a focus on media billing. In this role, you will play a vital part in supporting our media investment team, ensuring accurate and timely invoicing for our clients, and maintaining meticulous records of media budgets and vendor transactions. If you have a passion for media and finance, exceptional attention to detail, and thrive in a dynamic environment, we invite you to apply and become an integral part of our team.

The ideal candidate should be comfortable working in alignment with Eastern Time (ET).

You Will:

- Maintain oversight of client media budgets and requirements and develop and communicate media billing schedules
- Review and audit Media Authorization Forms alongside related vendor invoices.
- Provide support for SOX Testing, including documentation and assistance with selected samples
- Reconcile client billing and vendor invoices within the finance system
- Manage supporting backup documentation for month-end reconciliation
- Prepare ad hoc reports as necessary for internal and external purposes
- Coordinate campaign timelines and provide operational support to the investment team throughout campaign activation, including actualization and vendor invoice reconciliation.
- Assist with campaign setup, buy entry, and ongoing maintenance, ensuring all inputs align with client-approved budgets and Media Authorization Forms (MAFs).
- Collaborate with internal teams to deliver accurate status updates for billing purposes.
- Contribute to process improvement initiatives and support automation efforts to enhance efficiency in client and campaign deliverables.
You Have:

- Diploma or degree with a focus on accounting, finance, marketing, media, or a related field.
- 0–2 years of experience in accounting, finance, media operations, or a related environment.
- Strong accounting knowledge complemented by solid technical and analytical skills.
- Strong Excel skills, including the ability to work confidently with formulas, lookups, pivot tables, and data sets.
- Proficiency in Microsoft Office Suite, including Excel, Word, and Outlook.
- Familiarity with foreign currency transactions.
- Experience with Mediaocean, Prisma, or other media planning, buying, or financial management tools is a plus.
- Exceptional attention to detail and a high level of accuracy when handling financial, campaign, and billing data.
- Excellent written and verbal communication skills.
- Strong organizational skills and the ability to manage multiple priorities and deadlines.
- Ability to adapt and thrive in a fast-paced, dynamic environment.
- Self-motivated and capable of working independently with minimal supervision.
What We Offer

- Maternity and parental leave extra days
- Competitive benefits packages
- Vacation, compassionate leave, sick days, and flex days
- Access to online services for families and new parents
- Diversity and Inclusion Board with 12 affinity groups
- Internal learning and development programs
- Enterprise-wide employee discounts
- And more…
At Critical Mass, we value our employees and offer competitive compensation and benefits packages. If you’re looking for a challenging and rewarding opportunity to make a significant impact on the lives of our employees, we encourage you to apply for this exciting position today!

The Talent Team at Critical Mass is focused on ensuring we provide the best training, onboarding, and employee experience possible! Our new hires & employees are the future of our organization, and we want to set you up for long-term success. In an effort to do so, we expect our team to work from an office a minimum of 3 days a week.

The Ask Stems From Our Want To

Strengthen opportunity for continuous learning

Improve collaboration and team relationships.

Increase employee engagement

This work model balances the need for individual flexibility while maintaining the relentless customer focus we provide at CM. We understand that not everyone may feel comfortable with this expectation, so we ask that you please let us know immediately if there are any concerns so we can help navigate accordingly.

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Data: alder (https://alderhq.app). Cite https://alderhq.app/jobs/greenhouse%3Acriticalmass%3A8114082 and the date you read it. Observed facts come from the employer's own listing; location reach, level, family and skills are inferences.