How to Fix GRN and PO Bottlenecks in Construction with Modern Tech

Introduction - Fix GRN and PO Bottlenecks

If you’ve ever had a site manager call the office saying “materials are on site but the PO hasn’t been raised” , you’ve felt the frustration of a GRN (Goods Received Note) bottleneck.

It’s one of the biggest operational slowdowns in construction and engineering businesses.

For most SMEs, these delays don’t just cause admin headaches, they affect cash flow, supplier relationships, and project margins. Materials get delivered before the paperwork, invoices get held up waiting for approval, and finance teams spend hours chasing missing GRNs to match against POs.

At Jones Financial Accounts (JFA), we work with growing construction companies to eliminate these bottlenecks using simple, scalable technology. From mobile-based PO approval systems to live GRN tracking, small firms can now use tools once reserved for major contractors, without the enterprise price tag.

This article explains why GRN and PO delays happen, how modern tech fixes them, and what steps you can take today to free up your operations and keep your supply chain flowing.

For more practical advice on improving your site-to-office workflow, see our post on “The Top 5 Tech Stack for Construction Businesses” and grab our free Procurement & Approval Process Checklist from the Resources

Why it’s important

A GRN is the proof that materials or equipment ordered actually arrived, it ties a purchase order (PO) to a delivery and eventually to an invoice. In a perfect world, every delivery note gets signed, scanned, and matched to its PO within 24 hours.

But on construction sites, things rarely go that smoothly. Materials turn up while supervisors are busy, POs are raised late, and paperwork is left in site cabins or lost entirely. The finance team then can’t match invoices to jobs, causing:

• Late supplier payments (and strained relationships).

• Missing cost data in management accounts.

• Disrupted cash flow and delayed VAT recovery.

  
  

Many SMEs think “PO automation” is just for tier-one contractors. It isn’t. If your business turns over £500k+, every hour saved in approvals and reconciliations has a measurable impact on margin.

What You Need to Review

1. Site-to-Office Communication:How do POs get raised today? Are they emailed, handwritten, or system-based? Missing or slow approvals here are the root of all GRN delays.

   
   

2. Proof of Delivery Capture:Are GRNs digital? Are they uploaded immediately or waiting to be driven back to the office? Delays cause invoice backlogs and inaccurate job costing.

   
   

3. Supplier Terms:Do suppliers require GRN approval before invoicing? If so, every missing GRN delays the payment cycle.

   
   

4. System Integration:Does your purchase system link to your accounting software? Manual re-entry is where errors creep in.

   
   

5. Accountability:Who checks that deliveries match orders? Without clear ownership, everyone assumes “someone else will do it.”

   
   

Strategy — How to Fix It Using Modern Tech

Here’s how forward-thinking construction SMEs are solving their GRN and PO bottlenecks:

1. Cloud-based PO systems (like Procore, Tradify, or Joblogic).

• Supervisors raise purchase requests directly from a phone or tablet.

• Office teams approve instantly with email or app alerts.

• System auto-generates PO numbers, job codes, and budget tracking.

  
  

2. Mobile GRN capture.

• Drivers or site teams photograph the delivery note; the system tags it to the PO automatically.

• Some tools use QR-coded delivery notes, linking instantly to the right job and supplier.

• Result: finance can match POs, GRNs, and invoices same-day.

  
  

3. Integration with accounting software.

• Approved POs sync to Xero or Sage, meaning committed costs appear in real time.

• This improves forecasting accuracy and helps finance teams close the month faster.

  
  

4. Automation in approval hierarchies.

• Set spending limits: e.g., site supervisors approve up to £1,000, PMs up to £5,000, directors above that.

• Approvals route automatically via email or push notification, removing paperwork from the process entirely.

  
  

5. Real-time dashboards.

• Tools like Fathom or Power BI show live PO spend by job, outstanding GRNs, and supplier performance.

• Directors can see bottlenecks instantly and chase proactively, not reactively.

Real Numbers – Example from a £2M Construction Firm

A engineering client of JFA had an average invoice approval delay of 10 days, mainly due to missing GRNs.

By implementing a mobile-based PO and GRN system (Joblogic + Apron for payments):

• Invoice turnaround dropped from 10 days to 2.

• Supplier disputes reduced by 90%.

• They recovered £18,000 of unclaimed VAT previously missed due to lost paperwork.

• Admin time in finance fell by 30 hours per month, equivalent to one part-time staff member.

  
  

The entire rollout cost less than £250/month, paid back in savings within two months.

Misconceptions

1. “PO systems are only for big companies.”Wrong. Modern cloud tools scale by user count, even a 5-person construction business can automate purchasing for less than £100/month.

   
   

2. “Our suppliers don’t need GRNs.”They do. Even if they don’t ask for them, you need them to prove delivery and allocate costs correctly.

   
   

3. “Paper trails are safer.”They’re not. Paper fades, gets lost, and can’t be backed up. Digital copies are timestamped, searchable, and far easier to audit.

   
   

For more myths around automation, see our blog Should You Take That Opportunity? What the Numbers Reveal

3) Key Takeaways

• GRN and PO delays aren’t admin issues, they’re profit and cash flow issues.

• Mobile apps now let supervisors raise POs and upload GRNs in real time.

• Integration with your accounts system means finance can match and pay instantly.

• Even small firms can adopt this tech, it’s affordable, simple, and scalable.

  
  

Modern technology now lets construction businesses eliminate GRN and PO bottlenecks once and for all, improving supplier relationships, cash flow, and job profitability.

To start, download our free Procurement & Purchase Order Checklist to assess your current process, or book a discovery session with JFA to build a fully integrated system that connects site, operations, and finance.

Wrapping up today's insights, tomorrow we simplify another accounting challenge.