The verdict in three sentences
For an independent staffing agency placing 250 temporary workers a week, paper timesheets delay invoicing by 3 days, multiply payroll errors and tie up about 1 full-time administrator. A SaaS platform at £260 to £1,050 a month is enough if your clients accept its standard workflow, while a custom app at £35,000 to £70,000 makes sense when your sites, industrial clients and pay rules fall outside the box. The target: invoicing 3 days earlier and one admin role redeployed to business development.
The real cost of paper in a staffing agency
In the UK, independent agencies work heavily with logistics, food manufacturing, construction and industrial clients. Every week, 250 timesheets come back as photos, emails or paper drop-offs, often incomplete.
| Item | With paper timesheets | With mobile timesheets |
|---|---|---|
| Timesheet data entry | 25 h per week | 4 h of checks |
| Payroll and invoicing errors | 4 to 6% of timesheets | under 1% |
| Delay between week end and client invoice | 5 to 6 days | 2 to 3 days |
| Client approval of hours | calls and chasers | sign-off in the app |
| Assignment terms issued on time | 70 to 85% | 98% and above |
| Disputes over invoiced hours | 8 to 12 a month | 1 to 3 a month |
| Annual admin cost of processing | about £39,000 fully loaded | about £8,000 fully loaded |
Regulatory reminder: under the Conduct of Employment Agencies and Employment Businesses Regulations, terms must be agreed with workers before any assignment starts, and Key Information Documents are required. Digital issue and e-signature almost eliminate that compliance gap.
SaaS vs custom app: the 2026 comparison
Staffing software on the market (specialist vendors, timesheet platforms, temporary-work ERP modules) is mature. Custom development is mainly justified for agencies whose clients have very specific rules.
| Criterion | SaaS platform | Custom app |
|---|---|---|
| Entry cost | £1,700 to £8,700 of setup | £35,000 to £70,000 |
| Subscription | £260 to £1,050 per month | hosting £130 to £350 per month |
| Mobile timesheets | yes, standard workflow | adapted to each client and site |
| Pay rules (nights, Sundays, overtime) | limited configurable rules | all your rules and client agreements |
| eIDAS or UK-compliant e-signature | often optional, £1 to £2.60 per signature | integrated, cost depends on provider |
| Payroll export (Sage, IRIS, BrightPay) | standard formats | exact format of your payroll software |
| Client portal (approvals, invoices, documents) | basic | in your brand |
| Maintenance | included | 12 to 18% of initial cost per year |
Over five years, a platform at £700 a month with £5,200 of setup costs £47,200. A custom project at £52,000 plus £8,700 a year of maintenance and hosting costs £95,500. The gap must be covered by freed-up cash and fewer disputes.
The 3-day cash flow gain
| Assumption | Value |
|---|---|
| Hours billed per week | 250 workers x 35 h = 8,750 h |
| Average charge rate | £28 per hour |
| Weekly revenue | £245,000 |
| Annual revenue (47 weeks) | about £11.5 million |
| Invoicing 3 days earlier | about £105,000 of working capital freed |
| Overdraft or invoice finance cost avoided (4 to 6%) | £4,200 to £6,300 a year |
Mini case study
Tom, director of an independent staffing agency in Manchester (250 workers a week, £11.5 million revenue), chooses a custom app at £54,000. The administrator dedicated to data entry, costing £39,000 fully loaded a year, is redeployed to recruitment and business development.
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Disputes fall from 10 to 2 a month, saving an estimated £10,500 a year in credit notes and lost time, and the freed cash avoids £5,200 of invoice finance fees. Annual gain: 39,000 + 10,500 + 5,200 = £54,700. With £8,700 of maintenance, the project pays back in just over 14 months.
FAQ
Are e-signed assignment contracts valid?
Yes, an electronic signature is legally valid in the UK under the Electronic Communications Act and UK eIDAS. An advanced signature usually costs £1 to £2.60 per document with market providers.
How long does the app take to build?
Allow 4 to 6 months, including 4 weeks of testing with two or three pilot clients before moving all 250 workers.
Will temporary workers adopt the app?
Yes, if entry takes under 2 minutes a day. Equipped agencies reach 85 to 95% of timesheets entered on mobile after two months.
Is the payroll export reliable?
An export in the exact format of Sage, IRIS or BrightPay costs £2,600 to £5,200 and removes re-entry, the main source of payroll errors.
Where is worker data hosted?
With a UK or EU hosting provider, in line with UK GDPR. Allow £130 to £350 a month depending on volume and backup level.
Let's scope your project. We price your staffing app from your worker volume, clients and payroll software, with a budget range and a 4 to 6 month schedule. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
