It is Tuesday afternoon. You are on the kitchen extension across town, but your phone is buzzing because the bathroom fit-out you started Monday needs a decision on tiles, and the loft conversion you promised to "pop in on" hasn't been touched since Friday. Three jobs, one of you, and a creeping feeling that something billable is slipping through the cracks. Learning to manage multiple job sites at once is the difference between a profitable week and a chaotic one.
The good news: you do not need a project manager or a wall of sticky notes. You need a clean system for keeping each job separate, switching between them without confusion, and making sure every tracked hour lands on the correct invoice. This guide walks through exactly that, with a worked example of a builder running three sites Monday to Friday.
Why running 3+ jobs at once goes wrong
When you only have one job on, mistakes are obvious. Run three or more in parallel and the failure modes are quieter and more expensive:
- Mixed-up hours. You log two hours but cannot remember if they were the extension or the loft. At invoicing time you guess, and you guess low, because guessing high feels like overcharging.
- Materials on the wrong job. The EUR 180 of timber you bought "for the loft" actually went into the extension. One client gets billed for materials they never received; the other quietly eats the cost.
- Context-switching tax. Every time you jump between sites you lose a few minutes reorienting. Across a week that is hours of unbilled, unproductive time.
- The forgotten site. The job with the quietest client gets the least attention, runs late, and turns into the angry phone call you were trying to avoid.
The root cause is almost always the same: the jobs are not properly separated. Hours, materials, notes and tasks for three sites are swimming around in one head and one phone. Fix the separation and most of the chaos disappears.
One project per job: the single most important habit
The foundational move is simple. Set up one project per job site. Not one project per client, not one big "current work" bucket. One project for the kitchen extension, one for the bathroom, one for the loft. In Billr, a project is a self-contained container for everything about that single job.
Each project carries its own:
- Hourly rate. The extension might be GBP 45 an hour, the loft a flat day-rate job you logged differently. A per-project rate overrides the client default, so the right number is applied automatically.
- Time tracking. Every hour you track against that project rolls up into a running total, so you always know how many hours the bathroom has actually eaten.
- Budget tracking. Set a time estimate and a budget, and the project shows you earnings against budget as a percentage. You see the job creeping toward its limit before it blows past it.
- Kanban tasks. A board of tasks for that job (first fix, second fix, snagging) grouped by status, so the work left on each site is visible at a glance.
Once each job is its own project, the messy questions answer themselves. "How many hours on the loft so far?" Open the loft project. "Are we over budget on the bathroom?" The budget bar tells you. Nothing is mixed because nothing was ever in the same container.
The one-tap timer: track to the right job, every time
Separation only works if your time actually lands in the right place. This is where the one-tap timer earns its keep. Before (or during) a stretch of work, you pick the client and the project, then start the timer. The hour you just worked is now permanently attached to that specific job.
A few habits make this bulletproof when you are bouncing between sites:
- Pick the project before you down tools, not after. Start the timer when you arrive on site. Your selection sticks as you move around the app, so you can check a client detail or a task without losing your place.
- Stop the timer when you leave. Driving to the merchant or to the next site is not extension time. Stop, travel, then start the next project's timer when you arrive.
- Trust it to survive the day. The timer keeps running through app closes, backgrounding and even a phone restart, so a forgotten tap on a busy site does not cost you the whole afternoon. If the app was closed for a long stretch, Billr flags the gap and lets you keep or discount that time, so your hours stay honest.
- No signal on site? Keep tracking. The timer and your entries work fully offline and sync the moment you reconnect, which matters on a half-built loft with no Wi-Fi.
If you do forget to start the timer, do not guess at the end of the week. Use manual entry while it is fresh: pick the project, set the start time and duration, add a note. Three minutes at the end of each day beats a guessed total on Friday.
Switching context without losing the thread
The cost of running multiple sites is not just hours, it is mental load. The trick is to offload that load into the project itself so you are not carrying it in your head.
- Leave yourself notes on every entry. When you stop the timer, jot what you actually did: "ran first-fix wiring, waiting on plasterer." Next time you open that job you are instantly back up to speed.
- Use the task board as your memory. Move a task to "in progress" or "done" as you go. When you arrive on a site you have not touched in two days, the Kanban board tells you exactly where you left off, no scrolling through texts.
- Check the per-client time history. Each client's record shows the hours and earnings for today, this week and last week, plus any unpaid invoices. Before you call a client, a ten-second glance tells you where their job stands.
This is the real point of separation: when each job holds its own hours, materials, notes and tasks, switching sites stops being a mental reset and becomes a quick lookup.
Prioritising the week
Three jobs do not all deserve equal attention on any given day. A rough order of operations keeps the right plates spinning:
- Anything blocking another trade. If the plumber arrives Wednesday, your first fix has to be done Tuesday. Sequence-critical work comes first, even on a "quiet" job.
- The site closest to its budget or deadline. Open each project and glance at the budget bar. The job at 80% of budget with work remaining needs a plan, not another day of drift.
- The client who has gone quiet. The forgotten site is your biggest risk. Schedule a real visit before it becomes a complaint.
- Quick wins that free you up. A 30-minute snag that lets you invoice and close a job is often worth more than another half-day on a long one.
Billr does not have a calendar or scheduler, so this prioritising still happens in your own diary or head. What Billr gives you is the live data to prioritise well: real hours, real budgets, real status on every job, instead of a gut feel that always flatters the loudest client.
Making sure the right client gets billed for the right work
This is where the whole system pays off. Because every hour was tracked against a specific project, and every project belongs to one client, the billing is already sorted before you start. You are not reconstructing a week from memory; you are confirming what already happened.
When a job is ready to invoice, open that project and create an invoice straight from its uninvoiced time. Billr pulls in only that project's unbilled entries, applies the project's rate, and lays them out as invoice lines. The extension's hours go on the extension's invoice. The loft's hours go on the loft's. There is no risk of billing the bathroom client for loft work, because the two never shared a container.
For materials, add them as line items on the same invoice (or save your common ones in the item catalog so the EUR 180 of timber is one tap, not a re-typed line). Each job's materials sit on that job's invoice, with the labour, where they belong.
When the client pays and you mark the invoice paid, the linked time entries flip to "paid" automatically, so your records never drift and you can see at a glance which sites still owe you money.
Worked example: a builder running three sites Monday to Friday
Meet Dan, a builder with three live jobs this week. Here is how the one-project-per-job system carries him through:
- Project A: Kitchen extension for the Patels. Rate GBP 45/hr, budget GBP 6,000, currently at 60%.
- Project B: Bathroom fit-out for Mrs. Okafor. Rate GBP 45/hr, budget GBP 2,400, nearly done.
- Project C: Loft conversion for the Reyes family. Rate GBP 48/hr, budget GBP 9,000, early stage.
Monday. Dan arrives at the extension, picks Project A, taps start. He works 7 hours, stops for the drive to the merchant, then logs a quick 1-hour visit to the bathroom (Project B) on the way home, with a note: "fitted vanity, waiting on splashback tiles." Two projects, two clean blocks of time, zero confusion.
Tuesday to Wednesday. Full days on the extension. The budget bar on Project A ticks toward 75%, so Dan knows he has to tighten up the second fix or the job stops being profitable. The loft (Project C) is untouched, but its task board reminds him the steels are booked for Thursday, so it is sequenced, not forgotten.
Thursday. Steels go into the loft. Dan tracks the full day to Project C, leaves a note about the next steps, and moves two tasks to "done" on the board.
Friday. The bathroom is finished. Dan opens Project B, sees 18 tracked hours plus the vanity note, and creates an invoice straight from that uninvoiced time. He adds the EUR-equivalent materials line, sends Mrs. Okafor a pay link, and the job is billed before he leaves the driveway. The extension and loft hours stay exactly where they belong, ready for their own invoices when those jobs wrap.
No spreadsheet. No "I think it was about 20 hours." Three sites, every hour on the right job, every job ready to bill the right client.
Key takeaways
- One project per job site is the foundation. Each project holds its own rate, hours, budget and tasks, so nothing gets mixed.
- Pick client and project before you start the timer so every hour lands on the correct job, even offline.
- Use notes and the task board to offload mental load and switch sites without losing the thread.
- Prioritise by what is blocking other trades and what is closest to budget or deadline, using your live project data.
- Invoice straight from a project's uninvoiced time so the right client is billed for the right work, automatically.
Running several jobs at once will always be demanding, but it does not have to be chaotic. When each site is its own project and every hour is tracked to it, the week organises itself and the invoices write themselves. Set up a project for each of your live jobs in Billr and watch how much calmer your next busy week feels.
Frequently asked questions
Should I use one project per client or one per job?
One per job site. A single client can have several jobs running at once, and lumping them together makes hours and budgets impossible to separate. A project per job keeps each one's rate, time and tasks clean, and means you can invoice one finished job without touching the others.
How do I stop billing the wrong client for materials?
Track and add everything against the specific project from the start. Because each project belongs to one client, the materials and hours on that project can only ever appear on that client's invoice. Save your common materials in the item catalog so adding them is one tap and never lands on the wrong job.
What if I forget to start the timer on a site?
Use manual entry the same day while you still remember. Pick the project, set the start time and duration, and add a note. Doing it daily keeps your hours honest; reconstructing a whole week on Friday is where billable time gets lost.
Does Billr have a calendar to schedule my job sites?
No. Billr does not include a job calendar or scheduler, so your week still gets planned in your own diary. What Billr gives you is the live data to plan well: real tracked hours, budget progress and task status on every job, so you prioritise on facts instead of which client shouted loudest.
Can I see all my jobs and their progress in one place?
Yes. Your project list shows every job with its status and budget, and you can sort and filter to find the ones that need attention. Each client's record also shows their hours, earnings and unpaid invoices for the week, so you always know which sites are on track and which owe you money. See more in our project management tips.