The O2 customer service number depends on the type of customer you are. Here are the different numbers you can use to contact O2 customer service:

• From your O2 mobile: 202 (free)
• From a landline: 0344 809 0202 (standard UK rate)
• From abroad: +44 7860 980 202 (free)

If you are a business customer, you can call the following numbers:

• From your O2 mobile: 8002 (free)
• From a landline: 0800 977 7337 (free)
• From abroad: +44 7860 980 202 (free)

Its worth noting that O2 also offers additional support for customers who find it difficult to access their services due to a disability or personal situation. If you need help paying your bill, you can contact O2s Business Customer Service at 202 from your O2 phone or by using their Contact Us page.