| Alpha Guns London (Aldgate) | Shooting range | 63 Gower's Walk | Mon–Thu 12:00–21:00 |
| AlphaBiolabs | Drug testing service | 110 Union Rd | Mon–Thu 08:30–17:30 |
| Alyas International Enterprise Ltd. | Construction material wholesaler | 151 W Green Rd | Mon–Sat 08:00–20:00 |
| Alyse Baker Artistry | Hair & Makeup | Make-up artist | 41 Landells Rd | Daily 05:00–21:00 |
| Ama Oil And Gas Limited | Gas shop | Apt 807, 1 St Gabriel Walk | Daily Open 24 hours |
| Ama Sushi | Sushi restaurant | 49A Dartmouth Rd | Daily 12:00–22:00 |
| Amar Gaon | Bangladeshi restaurant | 50 Brick Ln | Daily 12:00–00:00 |
| Amara Clinic | Anaesthetist | 665 Finchley Rd | Mon–Sat 11:00–18:30 |
| Amber Security Systems Ltd | Servicio de seguridad | 242 Ellison Rd | Mon–Fri 09:00–17:00 |
| Ambrose King Sexual Health Centre | Specialised clinic | The Royal London Hospital, Mount Terrace | Mon–Tue 09:10–19:30 |
| Amélio | Pan-Latin restaurant | Ground Floor, 80 Paul St | Mon–Sat 12:00–22:00 |
| American Vintage | Clothes market | Stable St | Mon–Sat 11:00–19:00 |
| AMH Pianos Services London | Piano moving service | 1st Floor, 160-164 Gray's Inn Rd | Daily 08:30–22:00 |
| Amigo's Magic | Magician | 25 Hainthorpe Rd | Fri 07:30–23:30 |
| Amira Kitchen | East African restaurant | 26 New Park Rd | Daily 07:00–22:00 |
| Amitabha Garden | Buddhist supplies shop | 10 Wood Wharf | Mon–Fri 09:30–19:30 |
| Amora Gusto Tapas & Bar | Tapas restaurant | 94-95 Isabella St | Mon–Sat 12:00–23:00 |
| Amora Imani | Haute couture fashion house | Unit A, 66, 68 Bell St | Daily 11:00–19:00 |
| Ampersand Health | Research and product development | Queens Studios, 116-121 Salusbury Rd | Mon–Fri 08:30–18:00 |
| Ana Verdun London | Joyería | Barley Mow Centre, Barley Mow Passage | Mon–Fri 10:30–17:00 |
| Ananya Cards | Wedding service | First Floor, Creative ID & Ananya Limited, 85 Great Portland St | Daily Open 24 hours |
| Ancaster Nissan Eltham | Nissan dealer | 43-45 Eltham High St | Mon–Fri 08:00–18:00 |
| Anderson Acoustics Ltd | Acoustical consultant | Tempus Wharf, 33A Bermondsey Wall W | Mon–Fri 09:00–17:30 |
| Andrew the Locksmith Harrow | Emergency locksmith service | 43, Lime Court, Tranquil Ln | Mon–Fri 08:00–22:00 |
| Andrews Office Furniture - Camden | Office furniture shop | 414 Edgware Rd | Mon–Fri 08:30–17:00 |
| Angelina | Asian fusion restaurant | 56 Dalston Ln | Mon–Wed 18:00–23:00 |
| Animas Centre for Coaching | Coaching center | 86-90 Paul St | Mon–Fri 09:00–17:00 |
| Anjappar Chettinad Restaurant | Chettinad restaurant | 240 High St N | Daily 12:00–23:00 |
| Anna Fiorentini Stage & the City For Adults | Drama school | Head Office, G34A, 1 Dock Rd. | Mon–Fri 10:00–18:00 |
| Anna Fiorentini Theatre and Film School, Hackney Drama School | Drama school | College, BSix, Kenninghall Rd | Sat 09:30–14:00, 14:30–17:30 |