# FAQ - xAI API Billing
Frequently asked questions about xAI API billing.
## Payment Methods
### What payment methods are accepted?
- Credit cards (Visa, Mastercard, American Express)
- Debit cards
- Corporate cards
- Wire transfer (Enterprise only)
### How do I add a payment method?
1. Go to Billing → Payment Methods
2. Click "Add Payment Method"
3. Enter card details
4. Save
### Can I use PayPal?
PayPal is not currently supported. Please use a credit or debit card.
## Prepaid Credits
### How do prepaid credits work?
- Purchase credits upfront
- Usage is deducted from your balance
- No overage charges until credits are exhausted
- Credits don't expire
### What happens when credits run out?
- You'll receive notifications as balance gets low
- When exhausted, API calls may fail unless monthly billing is enabled
- Add more credits or enable monthly billing to continue
### Can I get a refund for unused credits?
Contact support@x.ai to discuss refund options.
## Monthly Billing
### How does monthly billing work?
- Usage is tracked throughout the month
- Invoice generated at month end
- Payment due within payment terms
- Available when prepaid credits are exhausted
### When am I charged?
Invoices are generated at the end of each billing period (monthly).
### What if I don't pay my invoice?
- Late payment notices sent
- API access may be suspended
- Contact support if you need to discuss payment arrangements
## Pricing
### Where can I find current pricing?
Visit https://docs.x.ai/docs/models for current model pricing.
### How are tokens calculated?
- Input tokens: Text/images sent to the model
- Output tokens: Generated response text
- Reasoning tokens: Internal model reasoning (Grok 4)
- Cached tokens: Repeated content (discounted)
### Are there any hidden fees?
No hidden fees. You're charged for:
- Token usage
- Tool invocations (where applicable)
- Any additional services you enable
## Invoices
### Where can I download invoices?
Go to Billing → Invoices in the Console.
### What's included in an invoice?
- Billing period
- Usage breakdown by model
- Token counts and costs
- Tool invocation costs
- Total charges
### Can I get a custom invoice format?
Enterprise customers can request custom invoice formats.
## Cost Control
### How do I set spending limits?
1. Go to Billing → Budgets
2. Set monthly limit
3. Choose action when limit reached (alert, throttle, or block)
### Can I set alerts for spending?
Yes, configure alerts in Billing Settings for:
- Daily spend thresholds
- Weekly spend thresholds
- Monthly budget warnings
### How do I reduce costs?
- Use cheaper models for simple tasks
- Enable caching for repeated prompts
- Optimize prompt length
- Use streaming only when needed
- Monitor usage regularly
## Tax
### Can I add my VAT/tax ID?
Yes, go to Billing → Tax Information and enter your tax ID.
### Are prices shown with or without tax?
Prices shown are typically before tax. Applicable taxes are added based on your location.
## Disputes
### How do I dispute a charge?
Contact support@x.ai with:
- Invoice number
- Specific charges in question
- Reason for dispute
### What's the dispute resolution timeframe?
We aim to resolve billing disputes within 5-10 business days.
## Enterprise
### What special billing options do Enterprise plans have?
- Custom contracts
- Volume discounts
- Net payment terms (Net 30, Net 60)
- Dedicated billing contact
- Custom invoicing
### How do I get Enterprise pricing?
Contact sales@x.ai for Enterprise pricing discussions.
