Introducing Flow: Our Next Chapter in Simple, Powerful Invoicing

Over the past month, we've been quietly evolving. What started as Billo Invoicing has grown into something bigger, more flexible, and more focused on helping you run your business with confidence.

Today, we're excited to share the next step in that journey:

Billo Invoicing is now Flow - from Acertine.

This isn't just a new logo and a fresh coat of paint. It's a reflection of where the product is today, and where we're taking it next.

Why we're rebranding from Billo to Flow

When we first launched as Billo, the goal was simple: make invoicing less painful for freelancers and small businesses.

As we've worked with more users, a few things became clear:

• You don't just "send invoices" - you manage ongoing work, time, projects, and relationships.
• You want invoicing that fits naturally into your daily flow, instead of feeling like admin tacked on at the end of the day.
• You need tools that are powerful enough for pros, but simple enough to enjoy using.

The name Flow better captures what we're really building:

• A product that fits into the natural flow of your work, especially if you bill by time, dates, or projects.
• A system that helps you move smoothly from work done → invoice sent → cash collected.
• A platform that lets your finances keep up with the pace of your business, without friction.

The brand change also aligns everything under our company identity, Acertine Ltd, and our new domains:

• App & marketing site: https://acertine.com
• Flow: https://flow.acertine.com
• Documentation & help centre: https://docs.acertine.com

What's changing

Here's what you'll notice as part of the rebrand.

1. New name, logo, and visuals

• Product name: Billo Invoicing → Flow
• Company name in-product: Acertine Ltd

We've updated logos and icons across:

• The web app
• PDF invoices and quotes
• Email templates (invoice reminders, quotes, payment links, onboarding, etc.)
• Marketing pages and Open Graph images

You'll see the Acertine green and the new Flow wordmark wherever Billo previously appeared.

2. New domains and URLs

We've moved from the billoinvoicing.com domain to our new home:

• App & main site: https://flow.acertine.com
• Docs & help centre: https://docs.acertine.com

Sitemaps, robots and supporting metadata are all aligned with the new domain.

If you have old bookmarks pointing at billoinvoicing.com, we recommend updating them, but we'll keep redirects in place so you're not disrupted.

3. Email addresses and sender details

All system emails now come from our new identity:

• Support: support@acertine.com
• General contact: support@acertine.com

Depending on the context, you may see:

• Flow <support@acertine.com>
• Your name + <support@acertine.com> (for example, when receipts are sent to your clients)

We've updated every email template - invoices, quotes, reminders, payment links, founder program, feedback, support and more - to use the new branding and email addresses.

4. Updated links in invoices, PDFs, and emails

Everywhere we previously referenced Billo or billoinvoicing.com, we now use Flow and the new domain:

• PDF footers and "generated with" lines now reference Flow and Acertine.
• Buttons and logos in:
  • Invoice emails
  • Payment link emails
  • View/preview emails
  • Reminder and receipt emails

all now point at https://flow.acertine.com with refreshed branding assets.

What's not changing

While the branding is new, the core of the product - and your account - stays the same.

Your data is safe

All your invoices, quotes, clients, settings and integrations remain exactly as they were. No migrations or manual changes are required on your side.

Your account & pricing

Your plan, limits and billing details are unchanged. This is a brand refresh, not a pricing change.

How the app works

You'll still find the same workflows you rely on today:

• Time-based invoicing (hours, days, weeks)
• Date-range calculations for work periods
• CIS support for UK construction
• Recurring invoices, templates and reporting

Everything remains where you expect it - just under a more coherent Flow brand.

Why this matters for you

A rebrand isn't just cosmetic. It's a commitment.

We chose Flow because we're doubling down on being the best choice for:

• Freelancers and small teams who need invoicing that feels natural, not bolted on.
• Time-based businesses - consultants, agencies, contractors - who bill by hours, days or weeks and want tools that actually understand that.
• UK businesses who need CIS and VAT handled properly, without having to become tax experts.

The new brand gives us room to:

• Ship more time-based features and workflow-focused improvements.
• Expand our documentation and onboarding at https://docs.acertine.com.
• Integrate more tightly with the tools you already use, under a name that fits the broader product vision.

What's next

Flow is still early in its journey, and the rebrand is a foundation for what comes next.

We'll be sharing more updates soon on:

• Smarter time and date-range workflows
• Deeper reporting and insights
• Tighter integrations with the tools you already use

If you have feedback or ideas on what would make Flow work even better for you, we'd love to hear from you at support@acertine.com.

Thanks for being part of this next chapter.