The verdict in three sentences
For a London travel management company (TMC) serving 120 corporate clients, margin leaks in the back office: re-keying tickets, checking travel policies, matching supplier invoices and monthly rebilling. Custom software between GBP 80,000 and 160,000, connected to the Amadeus GDS, applies each client's travel policy and produces a consolidated monthly invoice per cost centre. The measured gain is about 40 % of back-office time, with fewer rebilling errors.
The integrations that make the difference
A TMC lives on its connections. Without them, each booking is keyed two or three times: in the GDS, in the client spreadsheet, then in accounting.
- Amadeus GDS connection: automatic retrieval of PNRs, issued tickets, exchanges and refunds.
- Hotels and car hire: connectors to aggregators and negotiated rates in the UK and abroad.
- Travel policy per client: allowed cabin class by flight length, hotel caps by city, manager approval workflow.
- Client portal: travel request, one-click approval, history and receipts.
- Consolidated monthly invoicing: one invoice per company, split by cost centre and traveller, with service fees and UK VAT treatment.
- Accounting and BSP reconciliation: airline statements checked against tickets sold.
| Integration | Indicative 2026 budget | Time saved per month | Risk avoided |
|---|---|---|---|
| Amadeus GDS (PNRs, tickets, exchanges) | GBP 20,000 to 38,000 | 90 hours | Unbilled tickets |
| Travel policy and approvals | GBP 13,000 to 25,000 | 30 hours | Out-of-policy spend disputed by client |
| Client portal and app | GBP 15,000 to 32,000 | 40 hours | Requests lost in email |
| Hotels and car hire | GBP 10,000 to 22,000 | 25 hours | Negotiated rates not applied |
| Consolidated invoicing and VAT | GBP 12,000 to 25,000 | 60 hours | Rebilling errors |
| Accounting and BSP reconciliation | GBP 10,000 to 18,000 | 35 hours | Undetected BSP discrepancies |
Costs, timelines and alternatives in 2026
International online booking tools are powerful but charged per transaction and leave the client relationship partly on their platform. Custom software keeps your data, your brand and your margin.
| Criterion | Standard international tool | Custom software by Kolonell |
|---|---|---|
| Initial cost | GBP 5,000 to 15,000 setup | GBP 80,000 to 160,000 |
| Recurring cost | GBP 3 to 8 per transaction | Maintenance GBP 2,000 to 3,500 a month |
| Annual cost for 18,000 transactions | GBP 54,000 to 144,000 | GBP 24,000 to 42,000 |
| Consolidated invoicing with VAT split | Partial | Built in |
| Travel policy per client | Yes | Yes, unlimited rules |
| Agency branding on the portal | Limited | Full |
| Go-live | 1 to 2 months | 5 months |
From 10,000 to 15,000 transactions a year, custom software becomes cheaper within 2 to 3 years. Typical plan: scoping and flow mapping (3 weeks), Amadeus connection and booking core (8 weeks), travel policy, portal and invoicing (6 weeks), accounting, testing and training (4 weeks).
Mini case study
James, managing director of a TMC in London, manages 120 corporate clients and about 18,000 transactions a year. His 6 back-office agents spend about 700 hours a month on re-keying, checks and invoicing. At GBP 28 loaded hourly cost, that is GBP 19,600 a month.
With custom software at GBP 125,000:
- 40 % time saved: 280 hours a month, GBP 7,840 a month and about GBP 94,000 a year.
- Unbilled tickets recovered: around 0.5 % of volume, GBP 22,500 a year on GBP 4.5 million of ticketing.
- Annual maintenance: GBP 33,000.
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Net annual gain reaches about GBP 83,500, for a payback of around 18 months.
FAQ
How much does corporate travel agency software cost in London?
Budget GBP 80,000 to 160,000 for custom software connected to Amadeus, with travel policy and consolidated invoicing. Ongoing maintenance is GBP 2,000 to 3,500 a month.
Can an independent TMC connect to Amadeus?
Yes, through Amadeus APIs and the agency's existing GDS contract. API access fees vary with volume, typically GBP 5,000 to 15,000 a year.
Does it apply a different travel policy for each client?
Yes, each company has its own rules: cabin class, hotel caps by city, booking windows and approval chain. Out-of-policy requests are blocked or sent for approval in under 2 minutes.
Does the monthly invoice handle UK VAT correctly?
The consolidated invoice separates zero-rated air fares, standard-rated service fees and hotel costs, with client PO references. It exports to Xero, Sage or NetSuite.
How long does the switch take?
The typical timeline is 5 months. Cut-over is best done client by client, starting with 10 pilot companies for 3 weeks.
Let's scope your project. Share your number of clients, yearly transactions and GDS, and we will price a scope between GBP 80,000 and 160,000 with go-live in 5 months. 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.
