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Case study · Buzz OS

The operating system built for Buzz Accounting

Sales, jobs, staff capacity, new-client set-up, a client portal and tax filing with HMRC, in one system built from scratch for our own accountancy firm. It is in testing now and goes live in the firm once ISO 27001 certification is in place.

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Illustration of the Buzz OS job planner, with fictional client names
Illustration: the job planner. Client and staff names are fictional, because the real system holds real client records.

Why the firm built its own

Every practice-management product on the market was tried and turned down. Each one turned out to be a project-management tool with accountancy labels on it. None of them handled a sales list with two halves, staff capacity measured against real hours, and Companies House and HMRC data in a single flow. Getting all three meant three subscriptions and a person to reconcile them.

So the firm built the system it is moving onto, module by module. It goes live once ISO 27001 certification is in place, because a firm's client records deserve a standard someone else has audited.

Each module made the next one obvious

  1. 1Client records

    Each client record holds its Companies House data.

  2. 2Deadlines

    Filing dates come from that data, so nobody types them in.

  3. 3Jobs

    Recurring compliance jobs create themselves from the deadlines.

  4. 4Capacity

    Jobs carry hours, so each person's week can be measured.

  5. 5Planner

    The planner shows what every deadline does to the team's week.

Illustration of the Buzz OS toolkits screen, with fictional client names
Illustration: coaching and money toolkits. A client completes one on their own link and the result lands on their record.

One record per client

Everything the firm does for a client hangs off the same record: the Companies House data, the jobs and deadlines, the documents, the proposals and the tools the client has filled in.

Clients reach their side through a private link, so they approve proposals, answer requests and upload files without an account or a password.

Making Tax Digital

Fit to file tax returns with HMRC as an agent

This was the hardest stretch and the most valuable one. Filing as an agent is a different class of software, with a compliance bar to clear and no room for approximation. Buzz OS has been checked end to end against HMRC's own sandbox for every submission type, and its production approval pack is with HMRC.

  1. Digital records

    The bookkeeping records HMRC expects to be kept digitally.

    Verified in HMRC's sandbox
  2. Quarterly updates

    Cumulative updates sent each quarter for each business.

    Verified in HMRC's sandbox
  3. Year-end

    The adjustments and allowances that finish the tax year.

    Verified in HMRC's sandbox
  4. Final Declaration

    The figure the client agrees to, sent as the return.

    Verified in HMRC's sandbox

Six agents that draft and wait

The agents chase information requests, nudge new clients whose set-up has stalled, triage the inbox, pre-review jobs before a person reviews them, and walk each new client through set-up.

All six are built and in testing. Each one puts its work in an approval queue. Anything ignored twice goes to a partner.

Waiting for your approvalIllustration · fictional clients
  • AIInformation request agent
    Chase drafted for Northgate Joinery

    Bank statements for March and April are still missing. Second reminder, firmer tone.

    Approve
  • AINew client agent
    Nudge drafted for Harper & Co

    Engagement letter sent six days ago and not signed.

    Approve
  • AIInbox agent
    Reply drafted for Kestrel Interiors

    They asked about a van purchase. The answer cites the knowledge base entry it used.

    Approve
  • AIJob review agent
    Pre-review done on Tilford Bakery

    Debtors up on last year. A note is attached for the reviewer.

    Open
  • AIInformation request agent
    Chase for Marden Plant Hire ignored twice

    Moved to a partner to decide what happens next.

    Escalated

The decisions that shaped it

Build the layer, buy the engines

The firm still pays for Xero, BrightPay and its tax software. Those are regulated engines with their own compliance work, and rebuilding them would be reckless. What got built is the layer they plug into: the sales lists, the jobs, the capacity, new-client set-up and the client portal. That layer is where the firm's way of working lives, and no product fitted it.

Client portals with no login

Client software usually fails at the password. Ask a busy owner to create an account to approve one proposal and plenty of them stop there. Every client gets a private link instead, with no account to make. The same pattern runs e-signature, direct debit set-up and the new-client form.

Every agent drafts and none of them send

Nothing goes out unsupervised. Every draft lands in an approval queue, and anything ignored twice moves to a partner. The value is in the drafting and the noticing. The send button stays with a person on purpose.

An assistant that looks things up

Staff can ask the assistant about tax and about the practice. A model answering from memory would be wrong about rates and thresholds with total confidence. So it can only answer from a curated knowledge base and live practice data, and it is told to say when it does not know. Every question and answer is logged, and each answer has a button to send it to a partner.

Illustration of the matters screen in Buzz Legal colours, with fictional names
Illustration: the matters screen, in Buzz Legal's colours. Names are fictional.

The rest of the business

  • SalesTwo sales lists, one for new prospects and one for existing clients, with a price review suggested when turnover grows.
  • Taking on a clientProposal with discounts, engagement letter, e-signature, HMRC agent authorisation, anti-money-laundering check and direct debit.
  • Time and work in progressTime recorded against jobs, so each job shows whether it made money.
  • PeopleHR and holidays, a team hub, booking pages and a mobile app staff can install.

Next.jsSupabasePostgres with row-level securityClaudeHMRC Making Tax DigitalCompanies HouseXeroGoogle WorkspaceDocuSealAdfinNetlify

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